Everything from greeting to eating can be an opportunity to do the wrong thing, and not only embarrass yourself, but _______ your host.
____ our natural resources is very necessary.
_____ is known to us all is that the old scientist, for _____ life was hard in the past, still works very hard in his eighties.
—_____? —Fine, I’ve got used to the life there, and I’ve made some friends.
You’d better give the task to _____ you think can finish it ahead of time.
I don’t think John saw me; he _____ into space.