Kangaroos use their  long and powerful  tails for balance themselves when sitting upright or jumping. 
A.their
B.powerful
C.for
D.when sitting

There are about 350 species and subspecies of birds in danger of become  extinct, with a large number of them , 117 in all , found on oceanic islands.  
A.are
B.become 
C.of them 
D.in all

The total thickness of the ventricular walls of the heart are  about three times that of the atria. 
A.walls
B.are
C.about
D.that

When I entered  the room, I found my young son to stand on  the kitchen table.                        
A.entered 
B.found
C.to stand
D.on

The ASEAN Para-Games are hosted by the same country where the SEA Games took place.
A.organized        
B. impressed          
C.participated
D.defended

They decided to postpone their journey till the end of the month because of the epidemic.
A.put off          
B.take up
C.turn round  
D.do with

Everybody was panicked when the bomb exploded.
A.showed off      
B.went off         
C. took off        
D.turned up

Professor Berg was very interested in the diversity of cultures all over the world.
A. number          
B.changes    
C. conservation 
D. variety

According to the passage, human memory ______
A.can store less than what people thought       
B.was thought to be more efficient than it is supposed
C.is more complex than computer memory     
D. causes a lot of problems for researchers

The word that in paragraph 1 refers to ______.
A.human memory 
B.the problem  
C.the memory  
D. the sophistication