Peptit X có công thức sau: Gly-Ala-Val. Khối lượng phân tử của peptit X (đvC) là

A. 245. 

B. 281. 

C. 227. 

D. 209.

Read the following passage and mark the letter A, B, C, or D to indicate the correct word for each of the blanks from (1) to (10).

PROACTIVE JOB HUNTING

Once upon a time, people left school or university, joined a company and stayed with it until they retired. The concept of a job for life is now long (1) x , and nowadays many employees find it hard o stay loyal to their companies for even a relatively short period of time. According to a recent survey, this is particularly (2) x in London, where more than half of those asked said that they constantly (3) x one eye on other job opportunities, (4) x they are fairly happy in their existing job. A high number of London workers say that they are always on the (5) x , although they are content and motivated in their current position.

Job seekers find that the internet (6) x them with a quick and easy way to find out what's available, and 53 percent said that they had applied for a job or registered with an employment agency inthe past 12 months. This proactive (7) x means that people can look for a perfect job match with the (8) x of effort. But while this is good for job hunters, the growing lack of company loyalty could (9) x up being a big problem for employers .Perhaps surprisingly, the (10) x factors attracting job seekers was not more money, but challenging and interesting work.Question 9

A. run

B. come

C. end

D. lead

Phải dùng thể truyền để chuyển một gen từ tế bào này sang tế bào khác vì nếu không có thể truyền thì

A. gen không thể tạo ra sản phẩm nằm trong tế bào nhận.

B. gen vào tế bào nhận sẽ không nhân lên và phân li về các tế bào con.

C. khó có thể thu được nhiều sản phẩm của gen trong tế bào nhận.

D. gen cần chuyển sẽ không chui vào được tế bào nhận.