She looks very sad. I want to help her, but I just don’t know ____ to do it.
—__________—I’m from Japan. A. How are you? B. What’s your name? C. Where are you from?
I love places _____________ the people are very friendly.
---I am sorry to have kept you ___________. ---It doesn't matter. I've just come.
The number of students in our school_________ more than 2000.
At the science museum,the boys and girls get to know__________.