Cần phải có những biện pháp nào để nâng cao chất lượng vực nước nuôi thủy sản?

C1:-1/6+1/6+0

C2:-1/3+1/3+0

C3:-1/2+1/2+0

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.

Lisa was afraid the neighbors would despise her for not having a washing machine.

A. What a surprised the neighbors was that Lisa didn’t have a washing machine. 

B. Lisa was afraid the neighbors would know she didn’t have a washing machine. 

C. The neighbors felt sorry for Lisa because she didn’t have a washing machine. 

D. Lisa was afraid the neighbors would look down on her for not having a washing machine.

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 19 to 25.

  Foot racing is a popular activity in the US. It is seen not only as a competitive sport but also as a way to exercise, to enjoy the camaraderie of like-minded people, and to donate money to a good cause. Though serious runners may spend months training to compete, other runners and walkers might not train at all. Those not competing to win might run in an effort to beat their own time or simply to enjoy the fun and exercise. People of all ages, from those of less than one year (who may be pushed in astrollers) to those in their eighties, enter into this sport. The races are held on city streets, on college campuses, through parks, and in suburban areas, and they are commonly 5 to 10 kilometers in length.

          The largest footrace in the world is the 12-kilometer Bay to Breakers race that is held in San Francisco every spring. This race begins on the east side of the city near San Francisco Bay and ends on the west side at the Pacific Ocean. There may be 80.000 or more people running in this race through the streets and hills of San Francisco. In the front are the serious runners who compete to win and who might finish in as little as 35 minutes. Behind them are the thousands who take several hours to finish. In the back of the race are those who dress in costumes and come just for fun. One year there was a group of men who dressed like Elvis Presley, and another group consisted of firefighters who were tied together in a long line and who were carrying a fire hose. There was even a bridal party, in which the bride was dressed in a long white gown and the groom wore a tuxedo. The bride and groom threw flowers to bystanders, and they were actually married at some point along the route.

The word “costumes” as used in paragraph 2 most likely refers to

A. outfits

B. uniforms

C. cloaks

D. suits

Vì a,b thuộc N sao và a,b>2

=>a có dạng 2+m và b có dạng 2+n

ta có 2+m+2+n

=>4+m+n

lại có:(2+m).(2+n)

=>(2+m).2+(2+m).n

=>4+m.2+2n+mn

=>4+2.(m+n)+mn

Vì 4=4 mà 2.(m+n).m+n

=>a+b<a.b

Mark the letter A, B, C or D on your answer sheet to indicate the word whose differs from the other three in stress in each of the following questions.

A. appreciate

B. embarrassing

C. situation

D. experience

Cho 0,1 mol lysin tác dụng với dung dịch chứa 0,2 mol NaOH thu được dung dịch X. Cho X tác dụng vừa đủ với dung dịch HCl thu được dung dịch Y. Cô cạn cẩn thận Y thu được m gam muối khan. Giá trị của m là:

A. 33,6.

B. 37,2

C. 26.3

D. 33,4