passive form

a. My friend wrote this letter last week

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b. Lan will study hard in this year.

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c. they have bought this fan for a month

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d. Nam does this exercise

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viết một đoạn văn thể hiện cảm xúc, suy nghĩ của em về nếp sống thanh cao và giản dị của bác Hồ được gợi ra từ văn bản.

Câu 1:

Cấu trúc xoắn của NST do sự liên kết giữa ADN và protein histon có vai trò gì đối với tế bào?

2. a) Tìm số m ≥ 0 biết √25m = √3

b) Tìm số n ≥ 2 biết √144(n-2)=36

2. Tính độ dài cạnh y : biết BA =12; BC=20 tìm cạnh AC (y)

Câu 1: Cho ví dụ thực tế về di truyền, biến dị và di truyền học ?

I. complete with present perfect tense simple.

1. please wait. They ...................... (not finish) yet

2. .................... (you/ change) the colour of your hair?

3. she ............. (not send) us an invitation to her party.

4. we ............ (use) this recipe for chocolate cake many times.

5. ................( you / ever/ hear) a ghost ?

6. It................. (just / stop) raining.

7. I ................. (never /hear) such a stupid joke before!

8. ................. (they / forget) your phone munber?

9. She ............ (pay) the bill.

10. we ..................... (write) two tests today!

11. ...................... (you / do) all the housework?

I. Rewrite the sentences with used to .

1. Did you watch " Star Trek" on TV when you were young?

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2. He didn't study very hard when he was student.

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3. I waited for her at the bus stop every day.

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4. Claire ate an apple a day when she was at school.

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5. Did Mario exercise every day when he was a professional footballer?

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6.There was a huge tree in the middle of the park.

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7. We didn't like milk when we were kids.

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I.Complete with used to and the verd.
1. I .......... (not wake up) so early when I was at the camp.
2. ........................... ( they / sell) ice cream in the street in the past.
3. In the past, peolpe ............... ( not lock ) their door when they went out.
4. My dad ..................... (hunt) when he was a boy but now he doesn't like it.
5. Mun, ............... ( you / wear) a uniform at school?
6. It ............. (rain) a lot in the winter in my country.
7. He .......... ( not smile) very much; he was a grumpy old man.