—I saw Kate in the park this morning.—It ______ her. She moved to Canada last week. 

 —Mum, would you please buy me an MP5 player?—If you can help do the dishes the whole vacation, you ________ have one as a reward.

—I think the man over there must be Bob. -- It_______ be him. He has______ to Australia. 

—The similarities between social networks are striking.—That ________ come as no surprise，because they are all products of the Internet. 

The teacher told us the best way _____ English.