một phân tử adn dài 0,051 micromet.xác định số lượng nucleeotit và số vòng xoắn của phân tử ADN đó. Cho bết dố nucleotit loại Adeninchieems 30% tổng số nucleotit, hãy tính số lượng mỗi nucleotit từng loại, cho biết 1 micromet=10^4 A

giúp mk nha

Một con lắc lò xo dao động điều hòa với tần số 2 f 1 . Thế năng của con lắc biến thiên tuần hoàn theo thời gian với tần số

A. f 1 / 2

B.  2 f 1

C.  4 f 1

D.  f 1

Hoạt động của tuyến sinh dục chịu ảnh hưởng của hoocmon nào?

A. FSH.

B. LH.

C. Ostrogen.

D. FSH và LH.

______, I decided to stop trading with them

A. Despite of the fact that they were the biggest dealer

B. Though being the biggest dealer

C. Being the biggest dealer

D. Even though they were the biggest dealer

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions.

My first home

When my parents married, they rented a small house and they didn’t have a lot of money for furniture. The kitchen had a sink for washing up and a cooker, but that was all. They (28)______a old table and a chair from the market. They borrowed a sofa (29) ______was also old but they covered it with modern materials so it was bright and cheerful.

Outside, there was a small garden behind the house, but in front of it there was only the road. (30)_____, the road wasn’t busy, so I could cross it to reach the park on the opposite side. We lived there (31) ______I was ten and we were very happy. We had to move house because it was too small when my twin sisters were born. We all (32) ______sad when we left.

Điền ô số 29

A. whom

B. which

C. who

D. where