---Dad. Why I should stop__________ computer games? ---For your health, my boy, I’m afraid you _____________.
We are happy_______ you to the party for our friends from Beijing.
After reading for an hour, you'd better_______ the green trees for a minute or two.
Do you need help _______ your Maths homework?
Which floor do you_______ this tall building?
-How many students are there in your school? -There are about eight_______ students.