msin(2x) + cos(2x) = m-1. Tìm m?

a)  Các axit : HCl, HNO₃, HI, H₂SO₄, HClO₄,  HClO, HF, H₂SO₃, H₂CO₃, H₃PO₄, CH₃COOH, HNO₂. Nhận xét về dung dịch axit?

b) Các bazơ : NaOH, KOH, Ca(OH)₂, Ba(OH)₂, CsOH. Nhận xét về dung dịch bazơ?

d) Các muối : NaCl, KNO₃, (NH₄)₂SO₄, FeCl₃, MgSO₄, Al₂(SO₄)₃, Ba(NO₃)₂, K₃PO₄ , NaClO, KClO₃. Nhận xét về dung dịch muối?

e) Các muối : NaHSO₄, KHCO₃ , NaH₂PO₄, K₂HPO₄ , NaHS.  

Trong các chất trên, chất nào là chất điện li mạnh, chất nào là chất điện li yếu?

Nêu khái niệm : axit, bazơ, muối , hiđroxit lưỡng tính theo thuyết điện li?

Trong các chất vô cơ: axit, bazơ, oxit và muối thì chất nào là chất điện li? Vì sao?

1.   If I say that John is making out well in his work, I mean that he _____.

A. likes his work                      B. is succeeding        C. is leaving             D. is about to begin

2.   When one makes good time, he _____.

A. has a good time                                     B. travels at a good speed

C. is connected                                          D. has busy time

3.   To learn something by heart is to learn it _____.

A. quickly                              B. slowly                 C. well                    D. by memory

4.   One way of getting rid of something is to _____.

A. look at it                            B. admire it             C. keep it                D. throw it away

5.   If Mary’s purse goes well with her dress, then her purse and dress _____.

A. match                               B. are expensive       C. are pretty            D. are worn out

6.   Now and then means _____.

A. often                                 B. suddenly             C. early                   D. occasionally

7.   To make sure of something is to _____.

A. be certain of it                    B. call it off              C. turn it off             D. cancel it

8.   To keep house is to _____.

A. refuse to sell                                          B. lock the door against thieves

C. do the usual work in a house                    D. wash the house

9.   To be mixed up is to be _____.

A. happy                               B. worried               C. confused             D. late

10.      To see about something is to _____.

A. attend to it                         B. go to see it          C. admire it             D. look at it

11.      If I say that the meeting is over, I mean that the meeting has _____.

A. just begun                          B. ended                 C. been interesting    D. been called off

12.      If I say that I’d rather wait, I mean that I _____.

A. like to wait                         B. refuse to wait       C. prefer to wait       D. want to wait

13.      If I say that, after studying the message, I finally figured it out, this means that at last I _____.

A. answered the message                  B. understood it        C. put it away          D. picked it up

14.      If the month is up, this means that the period of one month has _____.

A. ended                               B. begun       C. seemed long                  D. been very warm

15.      To put off something means to _____.

A. look for it                           B. put it in place       C. cancel it              D. postpone it

16.      To get sick means to _____.

A. be sick                              B. become sick         C. be well                D. become well

17.      If the doctor says that you’d better do a certain thing, this means that _____.

A. you must do it                                       B. you are going to do it

C. it is advisable that you do it                      D. you prefer to do it

18.      To point out something is to _____.

A. need it                              B. touch it               C. look it up             D. indicate it

19.      By the way is a synonym for _____.

A. however                            B. at last                 C. incidentally           D. immediately

20.      If John arrives at a place on time and Mary arrives in time, who will possibly arrive first?

A. Mary                                                    B. John

C. John and Mary                                       D. Mary and John

Giải thích tính dẫn điện của dung dịch NaCl, HCl, NaOH?

1.       They never want me (eat)………………………………… whatever I want to.

2.       My parents let me (go)…………………………………….. out every weekend.

3.       During apartheid, Black people weren't allowed (sit) …………………………on White benches.

4.       Our English teacher wants us (work)…………………………………… hard.

5.       My mother made me (do)……………………………………. the housework yesterday.

6.       They didn't expect their children (be)………………………………….. serious during their absence.

7.        Where do you want her (meet)……………………………………… you?

8.       I would like you (stop)…………………………………………….. complaining

9.       I'm not allowed (drink)……………………………… or (smoke)…………………………. at home.

10.   They will never let me (wear)…………………………………… pearcings or have tattoos.

11.   I like listening (music)……………………………………… when I am tired.

12.   While she was in that country she spent all her days (sightsee)…………………….. the imperial cities.

13.   When I saw his performance, I couldn't help (laugh)………………………………………

14.   He gave up (smoke)……………………………………….. many years ago.

15.   I hate (sleep)…………………………………………… in the dark.

16.   Would you mind (post)……………………………………….. this letter for me.

17.   The trainers were very expensive; I couldn't afford (buy)………………………………. them.

18.   She proposed (meet)……………………………. me at the airport.

19.   He went out without (say)……………………………………… good bye.

20.   After they had finished (eat)………………………………………. they drove away.

21.   I couldn't avoid (meet)………………………………… him because he's my neighbour.

22.   My son is studying medicine and he wants (specialize)………………………………. in paediatrics.

23.   They enjoy (spend) ……………………………….their holidays with us in the South of France.

24.   Try (add)…………………………….. a little butter or cream to the batter, the crepes will be better!

25.   I suggest (call)……………………………. to reserve a table at the restaurant.

26.   I don't mind (stay)………………………………….. to keep an eye on Mary.

27.   I must remember (send)……………………………. the tax return before the end of the month.

28.   He refused (answer) ………………………………without the presence of his lawyer.

29.   I hope (see) …………………………….you soon in better form.

30.   My parents decided (welcome)………………………………. my boyfriend to dinner next Sunday.

31.   This house is very expensive and we hesitate (buy) ……………………………..it.

32.   I tried (explain) …………………………to him but he went on (grumble)……………………………….

33.   Try (forget) ……………………………. it. It isn’t worth (worry) ………………………….. about.

34.   We couldn’t help (laugh) ……………………………. when (see)…………………………him.

35.   We got tired of (wait)……………………….. for the weather (clear)…………………………….

36.   I remember (see) …………………………………….. him somewhere but I can’t tell where it was.

37.   He kept (stand) ……………………………….. up and (ask) …………………for an explanation.

38.   We regret (inform) …………………………….you that your application has been turned down.

39.   Did you advise him (see) ……………………………………. the doctor?

40.   Did you remember (lock) ……………the door? – No, I didn’t. You’d better (go) ………back and (do) …..… it now.

EXERCISE 2:

Many young people are fond of -------------- football and other kinds of sports.
A. play                             B. to play                              C. playing                                 D. played

They couldn’t help -------------- when they heard the little boy singing a love song.
A. laughing                       B. to laugh                            C. laugh                                 D. laughed

Your house needs -------------- .
A. redecorated                  B. redecorating                      C. being redecorated               D. to redecorate

I remember -------------- them to play in my garden.
A. to allow                        B. allow                                C. allowing                             D. allowed

It  was a nasty memory. Do you remember both of us wearing sunglasses to avoid -------------- by the supervisors?
A. to recognize                 B. to be recognized               C. recognizing                        D. being recognized

I can’t bear thinking back of that time. I’d rather -------------- equally.
A. treat                            B. be treated                         C. have treated                       D. treating

Did you accuse Nam of -------------- a plate? Well, I saw him -------------- it off the table with his elbow.
A. break/ knock                B. breaking/ knocking            C. to break/ to knock               D. breaking/ knock

We found it very difficult -------------- with Gamma.
A. to work                        B. work                                C. working                              D. worked

I can’t read when I am traveling. It makes me -------------- sick.
A. feel                              B. to feel                              C. felt                                    D. feeling

I need -------------- what’s in the letter. Why don’t you let me -------------- it?
A. to know/ to read           B. know/ read                       C. to know/ read                     D. knowing/ read

I suggest -------------- some more mathematical puzzles.  
A.  do                              B. to do                                C. doing                                 D. done

We regret -------------- you that we cannot approve your suggestion.
A. inform                          B. to inform                           C. informing                            D. informed

 The driver stopped -------------- a coffee because he felt sleepy.
A. have                            B. to have                             C. having                               D. had

Have you ever considered -------------- a pharmacist?
A.  become                      B. becoming                         C. to become                          D. became

You had better -------------- at home until you feel better.   
A. staying                        B. stayed                              C. to stay                               D. stay

I remember -------------- my mother said the grass in the garden needed --------------.
A. to hear/cutting              B. hear/cut                           C. heard/to cut                        D. hearing/ cutting

Peter sometimes help his sister --------------.
A. do homework               B. to do homework                C. with homework                   D. all are correct

 I would rather -------------- at home than --------------out with you.
A. staying/going                B. to stay/ to go                    C. stay/go                              D. stayed/went

I would rather you --------------.
A. drive                            B. to drive                             C. drove                                 D. driven

She didn’t say a word and left the room.
A. She left the room without saying a word                     B. She leaving the room without saying a word     
C. She left the room saying a word                                D. She left the room to say a word.

My father wanted me -------------- a pilot.                                                                      
A. become                       B. to become                        C. becoming                           D. became

Please wait a minute. My boss is busy -------------- something.
A. write                            B. writing                              C. to write                              D. to writing

My teacher doesn’t allow us -------------- while he is explaining the lesson.
A. talk                              B. to talk                              C. talking                               D. talked

We have plenty of time. We needn’t --------------   
A.  hurry                           B. to hurry                            C. hurrying                             D. hurried

I promised -------------- on time. I mustn’t -------------- late.
A. be/be                           B. to be/to be                        C. to be/ be                            D. be/to be

Mary and I are looking forward -------------- you.
A.  of seeing                     B. for seeing                         C. to seeing                            D. to see

I’m sure that he knows -------------- this new machine.
A. to use                          B. using                                C. how using                          D. how to use

Psychiatrists and doctors have failed -------------- people not to drink.      
A. to tell                           B. telling                               C. tell                                     D. told

29.   The students are used to -------------- in the school library.  
A. working                        B. work                                C. to work                              D. worked

Our room needs -------------- up.                                      
A. tidied                           B. to tide                              C. tidy                                    D. tidying

EXERCISE 3

1. As he had drunk too much, he didn’t drive home himself.

 Having………………………………………………………………………………………….……………

2. David did his homework and the went to bed.

After  having …………………………………………………………………...……………………

3. We have done two tests today, so we are exhausted.

We are exhausted about……………………………………………………….…………………………

4. She filled the washing machine and switched it on.

 Having…………………………………………………………………………….…………………………

5. She had not slept for two days and therefore she wasn’t able to concentrate.

Not……………………………………………………………………….………………………………

6. We read the book, then we wrote the assignment.

Before………………………………………………………………..………………………………

7. Since I had not seen him for ages, I didn’t recognize him.

Not…………………………………………………………………….…………………………………

8. He bought a radio. First he checked the price.

After …………………………………………………………………………………………………

9. It is easy for anyone to learn how to cook.

Learning…………………………………………………………...…………………………………

10. Mr.Jones would rather watch TV  at home than go to the cinema.

-> Mr.Jones prefers..............................................................

11.”You ought to study harder, Nam”

-> She advised ...................................................................

12.“You'd better look for a new job, Andrew.”

Jane advised................................................................................................................................................

13. “I must have made a mistake in the calculations.”

Mr. Forest admitted.....................................................................................................................................

14.“Perhaps we can go to Paris for the weekend.”

Neil suggested.............................................................................................................................................

15.“We'll organize the Christmas party.”

They promised............................................................................................................................................

16.“I wish I'd asked for his name and address.”

I regretted....................................................................................................................................................

17.“All right. We will meet the student representatives.”

The teachers agreed.....................................................................................................................................

18.“You mustn't drink too much caffeine.”

Marta warned.....................................................................................................................................

19.“If all goes to plan, I'll study medicine.”

Rachel hoped.....................................................................................................................................