He ______ at once when I promised to help him.

After retirement, she _____ herself in _______the poor children.

--- Hey, what’s up? Water is everywhere. What can I do for you? --- Oh, great. I ______ how to operate this damn new machine. 

When his mother came in, the boy pretended ______.

I’ve read a variety of science fictions, but few of them _____ the one that you lent me yesterday.