Several years ago， people knew Yao Ming .But now he is well-known all over the world， not only in China .

Think it over, _____ you’ll work out the math problem.

He has no ideawhat the book is aboutHehave read it very carefully

(2013·潍坊市高三二模)Sometimes smiles ________ be false, hiding other feelings like anger, fear or worry.

Alan ,don’t _________ too late, or you will feel sleepy in class. — Sorry, Mrs Black. I won’t do that again.