用方框中所给词组的适当形式填空。

avoid doing   assist with   at that point  in a rush   look back on   believe in

When I        those days, I realized I was desperately unhappy.
The lazy man tried every means to        his work.
It was        that I saw him leave.
We asked him to        us        the design of a new bridge.
I don’t believe what he said but I still        him.
The shark came        and the old man hit it as it shut its jaws.