It is very important for us to _______ between good and bad.

Did you __________ much time watching Li Na’s match last night? — Yes. It __________ me a few hours to watch this match.

I spent five yuan on this pen. =” I” spent five yuan buying this pen.

How long __________ your parents ___________? —For about twenty years.

Another cup of tea?— No, thanks. I _______ be off. My mom is waiting for me at home .