The box was _____ than I had expected. I was out of breath when I got home.
---Can you work out the maths problem? ---Sorry, I can ______ understand its meaning.
--- Are you worried when your son often plays computer games? --- Yes. I think playing too many computer games ______ on teenagers.
I won’t watch TV ______ I finish my homework.
---______ to give the letter to Mr. Wang. It’s very important. ---No, I won’t.
On the 40th Earth Day, Dr Wang gave us a talk on the importance of ______ the earth.