(-) His students don't take an important exam.

(?) Do his students take an important exam?

``

(-) Her grandma doesn't get up early everyday.

(?) Does her grandma get up early everyday?

-His students take an important exam .

(-) His students don't take an important exam

(?) Do his students take an important exam?

-Her grandma gets up early everyday.

(-) Her grandma doesn't get up early every day

(?) Does her grandma get up early every day?

his students don't take an important exam 

Do his student take an important exam?

her grandma doesn't get up early yesterday

does her grandma get up early yesterday?

3, D
4, B
5, D
10, B
11, A
12, B
13, C
14, A
15, D
16, B
17, B

mấy câu kia ok r ắ

1/ His teacher regrets _______ him that his application for the job has been turned down.

           A. tell             B. to tell                     C. telling                    D. tells

2/ The workers stopped _______ a rest because they felt tired.

           A. take B. to take                   C. taking                    D. took

3. At school, students usually take part in_______money for charity.

A. raised                B. to raise                     C. raising               D. raise

4.  Let's__________for a walk.

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

5. Why don't you consider to visit me? I really look forward to_______you.

A. see                     B. seen                   C. seeing                D. saw

6.  It's impolite___________people about their salary.

A. asked                B. to ask                      C. ask                     D. asking

7.  Don't_________in class.

A. talking              B. to talk                       C. talked                D. talk

8. Students are always interested in____________ a party.

A. to have              B. have                       C. having               D. had

9.___________the exams, students have to learn hard.

A. To pass             B. Passed                       C. Pass                   D. Passing

10. Would you please show me _________ yahoo messenger?

a. to use                     b. using                      c. how can I use          d. how to use

11. Mary told me _________ to go to the bank

a. don’t forget             b. not forget                c. not to forget d. should not forget

14. Let him _________ it himself

a. do                          b. to do           c. does                       d. doing

15. School children are looking forward to _________ on holiday

a. go                          b. be going                 c. going                      d. went

16. 

Mr. Minh _________ wearing a crash helmet when he goes somewhere on his motorbike

a. used to                    b. is used to                c. is using                   d. used

1. B
2. B 
3. C
4. A
5.C
6. B
7. D
8. C
9. A
10. D
11. C
12. A
15. C
16. B

a) \(CuO+2HCl\rightarrow CuCl_2+H_2O\)

b) \(n_{CuO}=\dfrac{4}{80}=0,05\left(mol\right)\)

Theo PTHH: \(n_{CuCl_2}=n_{CuO}=0,05\left(mol\right)\Rightarrow m_{CuCl_2}=0,05.135=6,75\left(g\right)\)

c) m_{dd sau pư} = 156 + 4 = 160 (g)

\(C\%_{CuCl_2}=\dfrac{6,75}{160}.100\%=4,21875\%\)

a, \(A=\dfrac{1}{7}.6+\dfrac{1}{7}.\dfrac{2}{7}+\dfrac{1}{7}.\dfrac{5}{7}=\dfrac{1}{7}\left(6+\dfrac{2}{7}+\dfrac{5}{7}\right)=1\)

b, \(A=\dfrac{4}{3}.\dfrac{13}{9}-\dfrac{4}{3}.\dfrac{40}{9}=\dfrac{4}{3}\left(\dfrac{13}{9}-\dfrac{40}{9}\right)=-4\)

c, \(A=\dfrac{5}{7}\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)=\dfrac{5}{7}.\dfrac{-7}{11}=-\dfrac{5}{11}\)

`A=6/7+[1/7(2/7+5/7)]`

`A=6/7+(1/7*1)`

`A=6/7+1/7`

`A=1`

~~~~~~~~~~~~~~~~~~~

`A=4/3*13/9-4/3*40/9`

`A=4/3(13/9-40/9)`

`A=4/3*(-3)`

`A=-4`

~~~~~~~~~~~~~~~~~~~

`A=5/7(5/11+2/11-14/11)`

`A=5/7(-7/11)`

`A=-5/11`

`A=6/7 + 1/7 . 2/7 + 1/7 . 5/7`

`A = 1/7 . 6 + 1/7 . 2/7 + 1/7 . 5/7`

`A = 1/7 . ( 6 + 2/7 + 5/7)`

`A=1/7 . ( 42/7 + 2/7 + 5/7)`

`A=1/7 . 7`

`A=1`

________________________

`A=4/9 . 13/3 - 4/3 . 40/9`

`A=(4.13)/(9.3) - (4.40)/(3.9)`

`A=(4.13-4.40)/(9.3)`

`A=(4.(13-40))/27`

`A=(4.(-27))/27`

`A=-4`

___________________________

`A = 5/7 . 5/11 + 5/7 . 2/11 - 5/7 . 14/11`

`A  =5/7 . ( 5/11 + 2/11 - 14/11)`

`A=5/7 . ((5+2-14)/11)`

`A=5/7 . (-7)/11`

`A=(5xx(-7))/(7xx11)`

`A=(-35)/77`

`A=(-5)/11`