Choose the best answer for the following sentence:
The majority of the TOEFL tests __________________ difficult. 
A. are            
B. is                 
C. be                  
D. being

Choose the best answer for the following sentence:
“Do you think the performers will be on time?”
''I don’t know yet. __________.'' 
A. They might have                
B. They seem
C. They might  
D. They can

Choose the best answer for the following sentence:
I have made __________________ friends with many local young people when we are on
the Green Summer every year.
 
A. a                              
B.  an                   
C.  the                    
D. no article

Choose the best answer for the following sentence:
Many teenagers are not much ________________ in reading books, except for what they are made to read at school. 
A. excited                         
B. important                  
C. slow                     
D. interested

Choose the best answer for the following sentence:
At last we came to _________ agreement that doing volunteer work would be a
chance for us to train ourselves.
 
A. a                       
B. an                       
C.  the                         
D. no article

Choose the best answer for the following sentence:
'' __________________ your tennis racket with you?'' ''Yes, I am going to show you how much I __________________ since last summer. I ________________ tennis lessons now.Now it ____________________ for you to judge if I __________________ any progress.'' 
A. Did you bring - improved - take - is - have made 
B. Have you brought - improved - take - was - have made 
C. Did you bring - have improved - am taking - is - made 
D. Have you brought - have improved - am taking - is - have made

Choose the best answer for the following sentence:
As teenagers, we always _____ each other very well. We still understand each other now.
A. understand
B. understood
C. were understanding
D. have understood

Nghiệm dương của phương trình : C3n-2+C3n-n=1 là
A. 1.
B. 3.
C. 2.
D. 0.

Hệ số của x5 trong khai triển (2x+3)8  là 
A. C83.23.35.
B. C83.25.33.
C. -C83.25.33.
D. C85.23.35.

Một bình đựng 4 quả cầu xanh và 6 quả cầu trắng. Chọn ngẫu nhiên 4 quả cầu. Xác suất để được 2 quả cầu xanh và 2 quả cầu trắng bằng:
A. .
B. .
C. .
D. .