_______ of my classmates could work out the maths problem because it was too difficult. 

—What do you think of the four classics(名著) of China? —I hear they are wonderful, but I’ve read _____ of them.

---How many students have visited Yangzhou Museum?  ---____

Clothing made of man-made fibers has certain advantages over ______ made of natural fibers like cotton，wool or silk.

All these changes will lead to a strong and powerful China,_____that can surprise the whole world.