When did you staying up so late?—When I entered this school two years ago, where students have too much homework to do.

What should I get _______ my dad?—How ________a tie?[ ]

So far, the moon ________ by man already.

You have a nice watch. — Thank you. I _______ it since two years ago.

When I passed the river, I saw some children ______ on the sand.