—There will be a talk show this time tomorrow.Would you go with me? —I'm sorry, but I ______ an important meeting.
— The government requires that every primary school student do sports for at least one hour every day. — _____. It is high time that students took exercise in order to build a strong body.
—Have you ever seen two leaves that are exactly the same? —Never. Leaves differ ____ each other ____ size and shape.
The only system I know ____ will help you remember what you have heard at a lecture is the system of keeping notes.
What difficulty will you have ____ people when you stay in a foreign country?
_____ I always felt I would pass this monthly exam, I never thought I would get an A. A. While B. Once C. As D. Because