Nguyên nhân chính làm cho hoang mạc phát triển mạnh ở châu Phi là do
A. một lục địa rộng lớn núi non bao bọc bốn phía.
B. lãnh thổ rộng lớn nằm chủ yếu trong đai khí hậu chí tuyến.
C. lãnh thổ trải ra hai bên Xích đạo.
D. được bao quanh bởi vùng biển có nhiều dòng hải lưu lạnh.

Choose the best answer for the following sentence:
______________ mortality rates are associated with many factors, including maternal realth, access to medical care, socio-economic conditions and public health practices.
A. Infant               
B. Immature                   
C. Juvenile                 
D. Youthful

Choose the best answer for the following sentence:
____________ is a sport in which people or teams race against each other in boats with oars. 
A. Rowing                   
B. Windsurfing                       
C. Swimming            
D. Water polo

Choose the best answer for the following sentence:
The baby __________________. 
A. was sleeping depth                      
B. was slept deeply
C. slept in depth                    
D. was sleeping deeply

Choose the best answer for the following sentence:
A man can never have too many ties. It’s ___________. 
A. unable          
B. impossible               
C. improbable             
D. incapable

Choose the best answer for the following sentence:
The teacher said that Vietnam _______________ to South-East Asia. 
A. has belonged                  
B. had belonged 
C. belonged                
D. belongs

Choose the best answer for the following sentence:
__________ you tell me if this bus goes to Heathrow Airport? 
A. Must   
B. May  
C. Should  
D. Could

Choose the best answer for the following sentence:
The ticket agent said that the plane would be boarding at ________________________. 
A. the gate six                   
B. sixth gate 
C. gate six                   
D. the six gate

Choose the best answer for the following sentence:
While hiking in Alaska, you have to keep an eye out for bears. If you see one, you _____________ approach it. It is dangerous. 
A. might not                 
B. may not                   
C. needn’t                   
D. must not

Choose the best answer for the following sentence:
China has a ____________ population than ____________ country
A. large - any
B. large - all other
C. larger - any other
D. larger - other