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

Sometimes smiles ______ be false, hiding other feelings like anger, fear or worry.

Nowadays, children under 1.4 meters _______________ be free to take buses in some cities. 

---I think _________________ in the morning is a good way to improve your spoken English. ---I agree with you.

---Could I use your bike? ---Yes, of course you_________.