Dolphins are interesting because they_________human behavior.at times.（）

People living in modern times benefit from many discoveries and inventions that have _________the world.（）

A．filled
B．stuffed
C．enriched
D．extended

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Jack：Say，Jane，let’s go and get a bite to eat.Jane：_________？Jack：How about McDonald’s？Jane：Great.（）

A．Where to 
B．What for 
C．How to 
D．Why so

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