It’s necessary for you _____ exercise every day.

—I have worked hard at math, but it seems that I haven’t made any progress.
—Keep on _____ at it, and you will be successful.
A. work B. working  C. to work 

—This physics problem is too difficult. Can you show me _____, Wang Li?
—Sure.
A. what to work it out  B. what to work out it  C. how to work it out

I advise you ________ to make computers serve us better.
A.  study   B. to study hard     C. studying hard

I prefer ________ at home rather than _________ out for a picnic on a rainy day.

It is necessary for us________ good habits in our daily life.

Our teacher often tells us _______ our own cloth bags when shopping.

Jim and his friends had great fun         at the pool.

Why not _________ down your mistakes in your notebook?
A. to write                B. writing          C. write

She wanted __________ some Beijing Opera.
A. to see                B. seen                C. seeing