The highway is covered with snow. I don't understand ________ they insisted on going by motorbike.

A．when 

B．why

C．whether 

D．how

________ Premier Wen Jiabao visited the United States led to the closer relationship between the two countries.

A．Which  

B．What

C．That 

D．As

What the doctors really doubt is ______ my mother will recover from the serious disease soon.

A．when 

B．if

C．whether 

D．what

Tom eagerly finished up ________ was left of the chicken pie.

A．what 

B．that

C．which 

D．where

I have no idea ________ the journalist could have got this information from.

A．that　　　

B．why 

C．which　　　

D．where

As a new diplomat，he often thinks of ________ he can react more appropriately on such occasions.

A．what 

B．which

C．that 

D．how

Could I speak to ________ is in charge of International Sales please?

A．who 

B．what

C．whoever 

D．whatever

It is obvious to the students ________ they should get well prepared for their future.

A．as 

B．which

C．whether 

D．that

Part of the reason Charles Dickens loved his own novel，David Copperfield, was________it was rather closely modeled on his own life.

A. what      

B. that 

C. why          

D. whether

—I prefer shutting myself in and listening to music all day on Sundays.

—That's________I don't agree. You should have a more active life.

A. where     

B. how  

C. when         

D. what