Speaking of all the songs he has written, I think this is probably his __________ one. 

As he works in a remote area, he visits his parents only _________.

Professor Lee failed many times but he ________found a good way to solve the problem.

I am not sure exactly how much money you will receive, but it will______cover your major expense.

—Could you tell Lucy about the news when you see her?—Sure, I will ________ I see her.