It is not uncommon for thereproblems of communication between the old and the young.

Do you know____ he will stay in America? –Ten weeks.

The worker keep_______ in order to make money for their living

I always go there by bus. — Why not ______ by train? It’s faster. [ ]

Miss Taylor never wastes money on anything too expensive, even though (尽管)she can _______ to. She has donated much of the money she saved to charities.