Hình chóp tam giác đều S.ABC có cạnh đáy bằng 3a, cạnh bên bằng 2a. Khoảng cách từ đỉnh S tới mặt phẳng đáy là:
A. $\displaystyle 4a.$
B. $\displaystyle 3a.$
C. $\displaystyle a.$
D. $\displaystyle 2a.$

Cho hình chóp $\displaystyle S.ABCD$ có đáy$\displaystyle ABCD$ là hình vuông và$\displaystyle SA\bot \left( ABCD \right)$, gọi$O$ là tâm hình vuông$\displaystyle ABCD$. Khẳng định nào sau đây sai?
A. Góc giữa hai mặt phẳng $\displaystyle \left( SBC \right)$ và$\displaystyle \left( ABCD \right)$ là góc$\widehat{ABS}$.
B. Góc giữa hai mặt phẳng $\displaystyle \left( SBD \right)$ và$\displaystyle \left( ABCD \right)$ là góc$\displaystyle \widehat{SOA}$.
C. Góc giữa hai mặt phẳng $\displaystyle \left( SAD \right)$ và$\displaystyle \left( ABCD \right)$ là góc$\displaystyle \widehat{SDA}$.
D. $\displaystyle \left( SAC \right)\bot \left( SBD \right)$.

Choose one sentence that has the same meaning as the root one:
I regret going to bed so late last night.
A. I wish I didn’t go to bed so late last night.
B. I wish I went to bed early last night.
C. I wish I hadn’t gone to bed so late last night.
D. I wish I could go to bed early last night.

Choose one sentence that has the closest meaning to the root one:
This pasta is a new experience for me.
A. I used to eat a lot of pasta.
B. I am used to eating pasta. 
C. It is the first time I have eaten pasta.
D. I have ever eaten pasta many times before.

Nội dung của Hiệp ước Muyních là
A. các nước tham dự hội nghị quyết định cho Xuyđét được quyền tự trị.
B. Anh, Pháp sẽ không giúp Ba Lan chống lại nước Đức.
C. Anh, Pháp trao vùng Xuy – đét của Tiệp Khắc cho Đức Quốc xã và Đức cam kết chấm dứt mọi cuộc thôn tính ở Châu Âu.
D. các nước tham dự hội nghị thống nhất sẽ không tấn công Liên Xô.

Choose one sentence that has the same meaning as the root one:
We stayed in our seats. The game ended.
A. We stayed in our seats after the game ended.
B. By the time the game ended, we stayed in our seats, c. 
C. We stayed in our seats until the game ended.
D. While the game ended, we stayed in our seats.

Choose one sentence that has the same meaning as the root one:
I regret lending him money.
A. I did not lend him money.
B. I wish I had lent him money.
C. He did not borrow money from me.
D. I lent him money and I regret now.

Choose one sentence that has the same meaning as the root one:
John did well in the competition, but he didn’t win.
A. Though having done well in the competition, John didn’t win.
B. In spite John did well in the competition, he didn’t win.
C. Despite doing well in the competition, John didn’t win.
D. Although John did well in the competition, however he didn’t win.

Choose one sentence that has the same meaning as the root one:
Sophie exchanged the shoes for a different pair.
A. One of Sophie’s shoes did not fit, so she returned them both.
B. Sophie took the shoes back to the store and got some different ones.
C. Because of a problem with the heel of the shoes, Sophie returned the shoes.
D. Sophie returned the shoes and took a pair of trousers instead.

Choose one sentence that has the same meaning as the root one:
“Would you like to come to my birthday party, Sarah?” asked Frederic.
A. Frederic asked Sarah if she liked his birthday party or not.
B. Frederic invited Sarah to his birthday party.
C. Frederic asked if Sarah was able to come to his birthday party.
D. Frederic reminded Sarah of his coming birthday party.