Once new difficulties _____ in our new job, we should learn to use our brains to solve them

Mr. Bean enjoys ___________ jokes and always makes us happy.

Tom can_____ the subway to the zoo, but he likes to go there_____ foot.

Canyou catch what 1 said—Sorry, I can_________ understand it.

If you go to the post office，would you please get me a stamp？　　 —I am ______ willing to.