【2013山东菏泽】The World Health Organization has given some advice on ______to protect us from being infected(感染) with H7N9.
It takes him too much time __basketball. He should spend more time __his homework.
He fell off the bike ________.
The students were all tired but ________ of them stopped ________.
He is a teacher. He has been a teacher ____ 1990.
Italy is famous for ________.