Is this ________ key, Tom? —No, that one is ________.

As time _________,we know each other better.

I feel it hard to keep up with my classmates in study and sometimes I lose heart. But whenever I want to ________ , my teacher always encourages me to work harder.

Well, Idothinktherabbitisabeautiful,gentleanimalwhichcanrunveryfast.– ______.

We should pay close attention to safety in schools because of frequent reports about accidents ____ students got injured or killed while in school.