He was so sick that he was sent to hospital 

Task 4: Choose the correct answers. Write A, B, C or D on the answer sheet. (0.2pt)

  1. After following his instructor’s guidance, he _______ great progress last year.

 A. did   B. made   C. played   D. went

 2. It is so difficult for someone_______ a percussion instrument professionally. 

A. to hear  B. to do   C. to play   D. to go

Ta có \(\sqrt{12+2\sqrt{35}}=\sqrt{7+2\sqrt{7.5}+5}=\sqrt{\left(\sqrt{7}+\sqrt{5}\right)^2}=\left|\sqrt{7}+\sqrt{5}\right|\)

mà \(\sqrt{7}+\sqrt{5}>0\) 

Suy ra \(\sqrt{12+2\sqrt{35}}=\sqrt{7}+\sqrt{5}\)

11. A

12. C

13. D

14. A

15. A

Áp dụng dãy tỉ số bằng nhau, ta được:

\(\dfrac{x}{5}=\dfrac{y}{9}=\dfrac{z}{3}=\dfrac{-x+y-z}{-5+9-3}=\dfrac{11}{1}=11\) \(\Rightarrow\left\{{}\begin{matrix}x=55\\y=99\\z=33\end{matrix}\right.\)

1. had left/ arrived

2. started/ had finished

3. went/ had got

4. had seen/ came

5. hadn't spoken/ moved

6. had got/ reached

7. brought/ had finished

8. hadn't thought/ saw

9. hadn't tried/ went 

D

Câu 80:

She _________ a bath two minutes ago.

A.have

B.has

C.having

D.had

Đáp án của bạn:

A  B  C  D

Câu 81:

The children __________ in the park at the moment.

A.playing

B.is play

C.are playing

D.plays

Đáp án của bạn:

A  B  C  D

Câu 82:

My mother __________ a meal now.

A.cooking

B.is cooking

C.cooks

D.cook

Đáp án của bạn:

A  B  C  D

Câu 83:

Be careful! The bus _______.

A.comes

B.come

C.coming

D.is coming

Đáp án của bạn:

A  B  C  D

Câu 84:

What__________ your mother ______ now?

A.do/ do

B.does/do

C.is/doing

D.will/do

Đáp án của bạn:

A  B  C  D

Câu 85:

Please be quiet! I _______.

A.is working

B.am working

C.are working

D.is/used to want

Đáp án của bạn:

A  B  C  D

Câu 86:

Sometimes I_______ up before the sun rises

A.get

B.got

C.gets

D.am getting

Đáp án của bạn:

A  B  C  D

Câu 87:

John __ tennis once or twice a week.

A.usually

B.is usually playing

C.usually plays

D.have usually played

Đáp án của bạn:

A  B  C  D

Câu 88:

It was noisy next door. Our neighbors _____ a party.

A.had

B.were having

C.had had

D.have had

Đáp án của bạn:

A  B  C  D

Câu 89:

It _______ dark. Shall I turn on the light?

A.is getting

B.get

C.got

D.has got

Đáp án của bạn:

A  B  C  D

Câu 90:

Tom: ‘I _______ for Christine. Do you know where she is?’ David: ‘She has gone out.’

A.look

B.looked

C.am looking

D.looks

Đáp án của bạn:

A  B  C  D

Câu 91:

Nga: ‘What were you doing at 7 o’clock yesterday evening?’ Huong: ‘I _______ my clothes.’

A.am ironing

B.have ironed

C.ironed

D.was ironing

Đáp án của bạn:

A  B  C  D

Câu 92:

Calvin: “Are you ready, Ann?” Ann: “Yes, I _______”

A.am coming

B.come

C.came

D.have came

Đáp án của bạn:

A  B  C  D

Câu 93:

Why __ at me like that? What’s the matter?

A.do you look

B.have you looked

C.did you look

D.are you looking

Đáp án của bạn:

A  B  C  D

Câu 94:

I _______ along the street when I suddenly heard footsteps behind me.

A.was walking

B.am walking

C.walk

D.walked

Đáp án của bạn:

A  B  C  D

Câu 95:

She _______ German for two years.

A.has learnt

B.is learning

C.learn

D.learns

Đáp án của bạn:

A  B  C  D

Câu 96:

The earth _______ round the Sun.

A.go

B.went

C.goes

D.has gone

Đáp án của bạn:

A  B  C  D

Câu 97:

I come from Canada. Where ___ you __ from?

A.do – come

B.did – come

C.are – coming

D.have come

Đáp án của bạn:

A  B  C  D

Câu 98:

When I last __ Jane, she __ to find a job.

A.see – trying

B.saw – was trying

C.have seen – tried

D.saw – tried

Đáp án của bạn:

A  B  C  D

Câu 99:

_______ you go to the dentist?

A.How often are

B.How often do

C.How often does

D.How are

Đáp án của bạn:

A  B  C  D

Câu 100:

Ann _______ tea very often.

A.doesn’t drink

B.don’t drink

C.didn’t drink

D.hasn’t drunken

7. You rarely read the articles on this website, __________?

A.do you           B. don’t you               C. haven’t you                D. did you

8. My brother doesn’t have an Iphone. He wishes he________ one.

A. has                         B. have                       C. had                         D. will have

9. Lan got up late, __________ she couldn’t catch the first bus.

A. as                           B. so                           C. when                      D. then

10. She suggested __________ to the beach for a change.

A. go                           B. to go                       C. going                      D. goes

11.Nam:“I’ve just finished my painting. Look!”            Tam: “_________ “

A. How cool!                                     B. I wish I could do it

C. Wow, I can’t imagine that.                     D. Sure

a. ĐKXĐ: \(x>0\)

\(P=\left(\dfrac{1}{\sqrt{x}}+\dfrac{\sqrt{x}}{\sqrt{x}+1}\right):\dfrac{\sqrt{x}}{x+\sqrt{x}}\)

\(=\dfrac{\sqrt{x}+1+x}{x+\sqrt{x}}.\dfrac{x+\sqrt{x}}{\sqrt{x}}=\dfrac{x+\sqrt{x}+1}{\sqrt{x}}\)

b. Để \(P=-1\) thÌ  \(\dfrac{x+\sqrt{x}+1}{\sqrt{x}}=-1\) 

\(\Leftrightarrow x+\sqrt{x}+1=-\sqrt{x}\)

\(\Leftrightarrow x+2\sqrt{x}+1=0\)

\(\Leftrightarrow\left(\sqrt{x}+1\right)^2=0\)

\(\Leftrightarrow\sqrt{x}+1=0\)

\(\Leftrightarrow\sqrt{x}=-1\) ( vô lý )

Vậy không có x thỏa mãn ycbt

c. Ta có \(x=\dfrac{8}{\sqrt{5}-1}-\dfrac{8}{\sqrt{5}+1}=\dfrac{8\sqrt{5}+8-8\sqrt{5}+8}{5-1}=\dfrac{16}{4}=4\)

Thay x=4 vào P, ta được

\(P=\dfrac{4+\sqrt{4}+1}{\sqrt{4}}=\dfrac{4+2+1}{2}=\dfrac{7}{2}\)

d. \(P=\dfrac{x+\sqrt{x}+1}{\sqrt{x}}\) \(\Rightarrow P-3=\dfrac{x+\sqrt{x}+1}{\sqrt{x}}-3\)

\(\Rightarrow P-3=\dfrac{x-2\sqrt{x}+1}{\sqrt{x}}=\dfrac{\left(\sqrt{x}-1\right)^2}{\sqrt{x}}\)

Mà \(\left\{{}\begin{matrix}\left(\sqrt{x}-1\right)^2\ge0\\\sqrt{x}>0\end{matrix}\right.\) \(\Rightarrow P-3\ge0\Rightarrow P\ge3\)

Dấu "=" xảy ra khi \(\left(\sqrt{x}-1\right)^2=0\Leftrightarrow\sqrt{x}-1=0\Leftrightarrow\sqrt{x}=1\Leftrightarrow x=1\)

Vậy \(P_{min}=3\) khi \(x=1\)