When the boss came in, the workers pretended ______ hard on their machines.

The answer is connected with the main use______ the body makes of food— to supply the energy for movement.

26个字母中有5个元音字母，它们是___________。

___________Mr Zheng ___________ Beijing last week— No, but he ___________ Beijing with his son next year.

d phoning her office, but Icouldn’t__________.