The three backpackers finally reached the top of Mount Huangshan, ________ they could enjoy the breathtaking sights to their heart's content.

A．when B．where

C．why D．how

Occasions are quite rare ________ I have the time to spend a day with my kids.

A．who B．which

C．why D．when

Mark drives his car too fast and, what's more, very carelessly, ________ worries his mother.

A．a　　B．what　　　

C．it　　　D．which

It's helpful to put children in a situation ______ they can see themselves differently.

A. that B. when

C. which D. where

Whenever I met her, ______ was fairly often, she greeted me with a sweet smile.

A. who B. which

C. when D. that

Gun control is a subject ______ Americans have argued for a long time.

A. of which B. with which

C. about which D. into which

I have reached a point in my life ______ I am supposed to make decisions of my own.

A. which B. where

C. how D. why

Life is like a long race ______ we compete with others to go beyond ourselves.

A. why B. what

C. that D. where

—What do you think of teaching, Bob?

—I find it fun and challenging. It is a job ______ you are doing something serious but interesting.

A. where B. which

C. when D. that

A person ______ e－mail account is full won't be able to send or receive any e?mails.

A. who B. whom

C. whose D. whoever