The main cause of HIV / AIDS infection in China is drug abuse,  ______ is very serious in Yunnan.

Today ________ number of people learning English in China ________ increasing rapidly. 

 Choosing a college major can be a difficult task, but it is nothing to take         .

 — Is the man our sales-manager? — No, it ______ not be him   he never plays cards.

.She ________the film. She knows nothing about it.