Cho các chất: etilen, but-2-in, toluen, stiren, propan, phenol. Số chất phản ứng được với dung dịch  Br 2  ở nhiệt độ thường là

A. 3.

B. 4.

C. 2.

D. 5.

Dòng điện chạy qua bóng đèn hình của một ti vi thường dùng có cường độ 30 µA. Số electron tới đập vào màn hình của tivi trong mỗi giây là

A.  1 , 875 . 10 14

B.  3 , 75 . 10 14

C.  2 , 66 . 10 - 14

D.  0 , 266 . 10 - 14

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

For a century before the Erie Canal was built, there was much discussion among the general population of the Northeast as to the need for connecting the waterways of the Great Lakes with the Atlantic Ocean. A project of such monumental proportions was not going to be undertaken and completed without a supreme amount of effort.

The man who was instrumental in accomplishing the feat that was the Erie Canal was Dewitt Clinton. As early as 1812, he was in the nation's capital petitioning the federal government for financial assistance on the project, emphasizing what a boon to the economy of the country the canal would be; his efforts with the federal government, however, were not successful.

In 1816, Clinton asked the New York State Legislature for the funding for the canal, and this time he did succeed. A canal commission was instituted, and Clinton himself was made head of it. One year later, Clinton was elected governor of the state, and soon after, construction of the canal was started.

The canal took eight years to complete, and Clinton was on the first barge to travel the length of the canal, the Seneca Chief, which departed from Buffalo on October 26, 1825, and arrived in New York City on November

4. Because of the success of the Erie Canal, numerous other canals were built in other parts of the country.

The pronoun “it” in the 3rd paragraph refers to which of the following?

A. The canal

B. The New York State Legislation

C. The state governor

D. The commission

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

Telecommuting is some form of computer communication between employees’ homes and offices. For employees whose job involve sitting at a terminal or word processor entering data or typing reports, the location of the computer is of no consequence. If the machine can communicate over telephone lines, when the work is completed, employees can dial the office computer and transmit the material to their employers. A recent survey in USA Today estimates that there are approximately 8,7 million telecommuters. But although the numbers are rising annually, the trend does not appear to be as significant as predicted when Business Week published “The Portable Executive” as its cover story a few years ago. Why hasn’t telecommuting become more popular?

Clearly, change simply takes time. But in addition, there has been active resistance on the part of many managers. These executives claim that supervising the telecommuters in a large work force scattered across the country would be too difficult, or, at least, systems for managing them are not yet developed, thereby complicating the manager’s responsibilities.

It is also true that employees who are given the option of telecommuting are reluctant to accept the opportunity. Most people feel that they need regular interaction with a group, and many are concerned that they will not have the same consideration for advancement if they are not more visible in the office setting. Some people feel that even when a space in their homes is set aside as a work area, they never really get away from the office.

The word “them” in the second paragraph refers to

A. telecommuters

B. systems

C.executives

D. responsibilities

The man and his dogs ________  were buried in the demolished building after the earthquake have just been rescued safely.

A. which    

B. who        

C. that         

D. whom