单项选择题
Those shirts are very expensive, do you know（）
A．how much cost them B．who do they cost C．they cost how much D．what they cost
单项选择题 （）we have finished the book, we shall start doing some exercises.
单项选择题 I can not help（）the box for you, as I am too tired.
单项选择题 It was not（）she took off her dark glasses（）I realized she was a famous film star.
