What is the main topic of this passage?
A.how asteroids and comets are studied  
B.new research on environmental damage
C.how the dinosaurs became extinct       
D.the effects of an asteroid hitting the Earth

________(44)
A.do 
B.make         
C.keep     
D.put

________(43)
A.previous 
B.fast 
C.following
D. formerly

________(42)
A.gradually        
B.remarkably   
C.normally       
D.definitely

________(41)
A.yet  
B.but  
C.never 
D.still

________(40)
A.counting     
B.relying      
C.needing  
D.depending

Various societies define ________ in many rather complex ways.
A. that is successful      
B.what success is
C.that success is         
D.what is success

The Icelandic language ______ very little over the past 800 years.
A.is changed    
B.has changed  
C.changes are
D.changing so

A: How long have you been here? B:____________      
A.For 6 hours.   
B.A month ago.
C.Since two weeks.            
D. For 10 o’clock.

Syndicated news___________than news from independent agents.
A.are cheaper and faster         
B.is cheaper and faster
C.are cheap and fast        
D.is cheap and fast