I know the difference between these two words. So （　） they.

A:know B:will C:do D:does

The saying goes that ______ everything is to know nothing.

A:knowing B:know C:to know D:having known

(It is) (extremely) important (for) an engineer (to know) to use a computer.

A:It is B:extremely C:for D:know

I know the difference between these two words. So （） they.

A:know B:will C:do D:does

W: I don't know why we listen to GeorgeM:______

A:I don' t know exactly why, either. B:I guess we are wrong this time. C:I know. But perhaps you don' t know why. D:George, you know, is one of the hardest working students among us.

I know the difference between these two words. So ______ they.

A:know B:will C:do D:does

(It is) (extremely) important (for) an engineer (to know) to use a computer.

A:It is B:extremely C:for D:know