Trong cấu trúc nhiễm sắc thể của sinh vật nhân thực, đơn vị cấu trúc gồm một đoạn ADN chứa 146 cặp nuclêôtit quấn quanh 8 phân tử prôtêin histon được gọi là

A. Nuclêôxôm

B. Crômatit

C. Sợi nhiễm sắc

D. Sợi cơ bản

I ,

1,D 2b 3c 4d 5 b 6c 7d 8d 9b 10a

II ,

1D 2C 3B 4D 5D 6B 7A 8C 9A 10B 11C 12B 13C 14A 15D

III ,

1, will play - to join 5, Do you hear - am listening

2, am not using 6, did not visit

3, am not having

4, is flying - is landing

IV ,

1, Businessman 2, Classmate

3,unfortable 4, medical 5, sunny

V ,

1, me - mine 3, so - as 5, the - by 7, to - of 9, very - much

2, drink - drinking 4, writting - bỏ 1 chữ t 6, an - a 8 , few - little 10, study -studies

VI ,

1, - What is Hanoi like ? 2, Where does Hoa go on Sunday ? 3, How long is Thanglong bridge in Hanoi ?

- It's beautiful She goes to the park and the zoos . Thanglong bridge is the longest one in Hanoi .

4, Why does she like the parks ? 5, What kind of animal does she like best ?

Because they are big , green and there are many beautiful flower . She like Money best .

VII ,

1, \(\rightarrow\) Lan has long hair 2, \(\rightarrow\) Nam goes to school by bike everyday. 3, \(\rightarrow\) Nga is the most intelligent than in our class

4,\(\rightarrow\) Shall we go swimming ? 5, \(\rightarrow\) What is your date of birth ? 6, \(\rightarrow\)What is the height of this building ?

7, \(\rightarrow\)Miss Lan teaches English 8 , Mr . Hoang spent half an hour to walk to work to yesterday .

9, \(\rightarrow\)How much is this cap ? 10 , \(\rightarrow\) I prefer listening to music to watching TV.

VIII,

1,C 2,B 3, D 4, D 5, A 6,B 7,B 8, D 9,C 10 , B

IX ,

1,about 2, on 3, from 4, in 5,about 6, in 7, for 8, for 9, to 10 , into

X ,

1, I pleased to hear that you and your family are well .

2, here is the photo of my family and let me tell you about us .

3, My father is a mechanic . He work in a factory in the suburb .

4, He work five days a week from Monday to Friday .

5, He usually goes to work by motorbike in the morning so he is not free every morning .

6, In the freetime my father often playing badminton with friends .

7, My mother is teacher . She teaches math in a school near my house .

8, My brother is 17 years old and he is in grade 12

9, He love collecting stamps . He has hundreds of stamps in his collection.

10, Please write to me room and tell your family .

Chúc Bạn Hok Tốt !

Cho số phức z 1 = - 3 + 2 i  và  z 2 = 2 - i   . Tìm môđun của số phức  2 z 1 - 3 z 2   .

Cho các hợp chất hữu cơ sau: phenol, axit acrylic, anilin, vinyl axetat, metylamin, glyxin. Trong các chất đó, số chất làm mất màu nước brom ở nhiệt độ thường là

A. 2

B. 4

C. 3

D. 5

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 34 to 40.

An air pollutant is defined as a compound added directly or indirectly by humans to the atmosphere in such quantities as to affect humans, animals, vegetation, or materials adversely. Air pollution requires a very flexible definition that permits continuous change. When the first air pollution laws were established in England in the fourteenth century, air pollutants were limited to compounds that could be seen or smelled - a far cry from the extensive list of harmful substances known today. As technology has developed and knowledge of the health aspects of various chemicals has increased, the list of air pollutants has lengthened. In the future, even water vapor might be considered an air pollutant under certain conditions.

Many of the more important air pollutants, such as sulfur oxides, carbon monoxide, and nitrogen oxides, are found in nature. As the Earth developed, the concentration of these pollutants was altered by various chemical reactions; they became components in biogeochemical cycles. These serve as an air purification scheme by allowing the compounds to move from the air to the water or soil. On a global basis, nature's output of these compounds dwarfs that resulting from human activities. However, human production usually occurs in a localized area, such as a city. In such a region, human output may be dominant and may temporarily overload the natural purification scheme of the cycles. The result is an increased concentration of noxious chemicals in the air. The concentrations at which the adverse effects appear will be greater than the concentrations that the pollutants would have in the absence of human activities. The actual concentration need not be large for a substance to be a pollutant; in fact, the numerical value tells us little until we know how much of an increase this represents over the concentration that would occur naturally in the area. For example, sulfur dioxide has detectable health effects at 0.08 parts per million (ppm), which is about 400 times its natural level. Carbon monoxide, however, has a natural level of 0.1 ppm and is not usually a pollutant until its level reaches about 15 ppm.

Which of the following is best supported by the passage?

A. To effectively control pollution, local government should regularly review their air pollution laws

B. One of the most important steps in preserving natural lands is to better enforce air pollution laws

C. Scientists should be consulted in order to establish uniform limits for all air pollutants

D. Human activities have been effective in reducing air pollution