Cho hình lăng trụ đứng A B C . A ' B ' C '  có đáy là tam giác vuông cân tại đỉnh A, mặt bên B C C ' B '  là hình vuông, khoảng cách giữa A B '   v à   C C '  bằng a. Thể tích của khối trụ A B C . A ' B ' C ' .

A. a 3

B. 2 a 3 2

C. 2 a 3 3

D.  2 a 3

Trong không gian với hệ tọa độ Oxyz, mặt cầu (S) có bán kính bằng 2 tiếp xúc với mặt phẳng (Oyz) và có tâm nằm trên tia Ox. Phương trình của mặt cầu (S) là

A.  S :   x + 2 2 + y 2 + z 2 = 4

B. S :   x 2 + y - 2 2 + z 2 = 4

C. S :   x - 2 2 + y 2 + z 2 = 4

D. S :   x 2 + y 2 + z - 2 2 = 4

Silence __________ the theatre as the audience awaited the opening curtain with expectation and excitement.

A. fell in with

B. came between

C. hung over

D. dropped out of

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.

Where in the passage does the author mention a committee that worked to develop the canal?

A. The first paragraph

B. The second paragraph

C. The fourth paragraph

D. The third paragraph

Trong không gian Oxyz, mặt phẳng (P): x + 2y - 6z - 1 = 0 đi qua điểm nào dưới đây?

A. B(-3;2;0)

B. D(2;1;-6)

C. A(-1;-4;1)

D. B(-1;-2;1)