6. They would rather Nam didn't smoke in the office.

7. You should practice speaking English every day.

8. What did you talk to him last night?

9. It isn't easy to learn English in a short time.

20. Your room is larger and more comfortable than ours.

6.      They would rather Nam not smoking in the office.

7.      You should practice speaking English every day.

8.      What did you talk to him about last night?

9.      It’s not easy learning English in a short time.

10.  Your room is larger and more comfortable than ours.

Ex1 ko có verb à

Ex2

1 like

2 listen

3 wears

4 teaches

5 do

6 goes

7 comes

8 goes

9 watch

10 walks

11 is

12 washes

13 studies

14 wants

15 plays

16 buys

17 studies

18 tries

19 washes

20 cries

21 says

22 flies

23 don't have

1 is

2 are

3 is

4 am

5 are

6 is

7 is

8 are

8 are

10 is

11 are

12 is

13 am

14 are

15 are

làm ơn giup mk với

\(9,=\dfrac{\sqrt{5}+1-\sqrt{5}+1}{\left(\sqrt{5}-1\right)\left(\sqrt{5}+1\right)}=\dfrac{2}{4}=\dfrac{1}{2}\\ 10,=\dfrac{\sqrt{5}+2+\sqrt{5}-2}{\left(\sqrt{5}-2\right)\left(\sqrt{5}+2\right)}=2\sqrt{5}\\ 11,=\dfrac{8+6\sqrt{2}-8+6\sqrt{2}}{\left(4-3\sqrt{2}\right)\left(4+3\sqrt{2}\right)}=\dfrac{12\sqrt{2}}{-2}=-6\sqrt{2}\\ 12,=\dfrac{2+\sqrt{6}+2-\sqrt{6}}{\left(2-\sqrt{6}\right)\left(2+\sqrt{6}\right)}=\dfrac{4}{-2}=-2\\ 13,=\sqrt{2}-1+\sqrt{2}+3=2\sqrt{2}+2\\ 14,=2-\sqrt{3}+\sqrt{3}-1=1\\ 15,=3-\sqrt{5}+\sqrt{5}-2=1\)

Một gen có 2400 nucleotit ⇒ N = 2400 Nu

⇒ Số chu kì xoắn là:

C = N : 20 = 2400 : 20 = 120 (chu kì)

Chiều dài đoạn phân tử ADN:L=N/2.3,4

               =>L=2400/2.3,4=4080 (A^o)