She brought with her three friends, none of       I had ever met before.

A．them

B．who

C．whom

D．which

The how-to book can be of help to       wants to do the job.

In the room ______ window is wide open ______.

_________we sleep together or apart is one of the biggest cultural differences, and only in western societies ______ the feeling that babies should sleep apart from their parents.

____ they are closest friends is not clear though they live together.

A tunnel was built under _____ was a lake a year ago.

—Mary, don’t you believe your sister?
—Yes. I believe _____ she says.

Today impressionist paintings are accepted as the beginning of ______ we call “modern art”.

—Sir， can I pass the examinations this time？
—That depends on　　　　you work hard enough or not.
what  B. that  C. whether  D. how

— That boy enjoys drawing very much.
—____, I have never seen anyone else who is as enthusiastic about drawing as he is.