________ help the people in the snowstorm in the south made him worried．

A．Not known how to

B．Unknown what to do to

C．His knowing not how to

D．His not knowing how to

I smoke out of ________ habit, not for ________ pleasure, and I have had this habit for twenty years．

A．a; the

B．the; a

C．/; the

D．/;/

________ hearing the bad news, Shirley began to cry．

A．In

B．For

C．On

D．With

We haven’t discussed yet ________ we are going to place our new furniture．

A．that

B．which

C．what

D．where

John's success has nothing to do with good luck．It is years of hard work _________ has made him what he is today．

A．why

B．when

C．which

D．that

Listen! Do you hear someone _________ for help?

A．calling

B．call

C．to call

D．called

It rained heavily in the south, ________ serious flooding in several provinces．

A．caused

B．having caused

C．causing

D．to cause

Mrs．White showed her students some old maps ________ from the library．

A．to borrow

B．to be borrowed

C．borrowed

D．borrowing

Mark ________ have hurried．After driving at top speed, he arrived half an hour early．

A．needn’t

B．wouldn’t

C．mustn’t

D．couldn’t

People have always been ________ about exactly how life on earth began．

A．curious

B．excited

C．anxious

D．careful