Một nguồn điện có suất điện động ξ = 12 V  điện trở trong r = 2 Ω  nối với điện trở  tạo thành mạch kín. Xác định R để công suất tỏa nhiệt trên R cực đại, tính công suất cực đại đó

A.  R = 1 Ω ,   P = 16 W

B. R = 2 Ω ,   P = 18 W

C. R = 3 Ω ,   P = 17 , 3 W

D. R = 4 Ω ,   P = 21 W

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

Scientists say that (44) _______ the next thirty years we will not be able to tell the difference between the real people and the virtual people- that is, people created by computer. These virtual humans are already in films and computer games and engineers are setting up experiments to see if they can develop a (45) _______ feeling virtual people. And the prediction is that these virtual people will be better than us humans- because they are basically a machine, they can (46) _______ data and remember it much better than we can. In addition, they are starting to look much more like us. They are already used to (47) _______ research that may be dangerous for humans, such as on equipment for the army. The “virtuals” are very good at following procedures exactly so scientists can get reliable results. Engineers are carrying out further tests to find out how to get the virtual beings to understand conversation. Now, we can only “talk” to them by typing. But if you (48) _______ the internet, you will find more and more sites devoted to virtual humans- we are just at the beginning of what they can do.

Điền vào ô số 46

A. gather

B. accumulate 

C. amass 

D. collect

Cho các phân tử sau: H₂, N₂, HCl, H₂O, CO₂. Số phân tử không phân cực là

A. 1.

B. 2.

C. 3.

D. 4.

Bác Hồ

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 30 to 34.

A Working Vacation

Have you ever wondered what it would be like to get your dream job? It can take years to get the education and develop the skills you need for the perfect job. However, there is a way to experience your dream job without having to get the required training or degree. Since 2004, Brian Kurth’s company, Vocation Vacations, has been connecting people with mentors who have the jobs of their dreams.

Kurth had been working for a phone company before starting his own company. He didn’t like his job, and he had a long time to think about it on his drive to and from work. He also thought about his dream job while driving. He was interested in becoming a dog trainer, but he didn’t want to take any chances and switch to a field he didn’t have experience in. He really wanted to know what the job was like and if it was realistic for him to work towards his goal. So, he found a mentor – a dog trainer that could tell him about the job and everything it involved. After that, he helped his friends find mentors to explore jobs they were interested in. They thought it was helpful to talk to people who had their dream jobs before spending lots of time and money getting the training they needed for those jobs.

Kurth saw how much this helped his friends, so he decided to turn it into his business. He started Vocation Vacations in 2004, and by 2005, the company was offering experience with over 200 dream jobs. Today, about 300 mentors work with the company to share their knowledge about their jobs. Customers pay to experience the job of their dreams and work with these mentors to see what a job is really like. A “job vacation” costs between $350 and $3,000 and can be for one to three days. Many people use Vocation Vacations to see if their dream job is a career path they want to continue. Others do it just to experience the job of their dreams one time.

Vocation Vacations jobs are in the fields of fashion, food, entertainment, sports and animals. Many people want to try glamorous jobs. For example, they want to try working as actors, music producers, photographers and fashion designers. According to Kurth, some other popular dream jobs are working as bakers, hotel managers and wedding planners.

Sourcea: Summit 2 by Pearson Education, 2017

The word “their” in paragraph 3 refers to _______.

A. jobs

B. mentors 

C. customers 

D. experiences 

ở cà chua có cả cây tứ bội và cây lưỡng bội. Gen A quy định quả màu đỏ là trội hoàn toàn so với alen a quy định quả màu vàng. Cho các phép lai sau:

(1). AAaa x Aa   

(2). AAaa x aaaa        

(3). AAaa x AAaa

(4). AAaa x aa    

(5). AAaa x Aaaa       

(6). Aaaa x Aaaa

Số phép lai cho tỉ lệ phân li kiểu hình 11 quả màu đỏ : 1 quả màu vàng ở đời con là 

A. 2

B. 3

C. 4

D.1