--What's this? --It's__ backpack. --Where's__ backpack?--It's on the bed.
I haven’t heard ________ Jim yet for a long time.
______I got up early this morning, I couldn't catch the early bus.
The environment in our city ____ greatly if we make every effort in the near future.
________ the girls in our class ________ over twenty.
We planted _______ trees last year.