Li Lei realized necessary for him to get up early to do some exercise for he found he was getting fatter and fatter..
The World Health Organization has given some advice on________to protect us from being infected(感染)with H7N9.
—What do you usually help your mother________? —I often do the dishes.
It took him one hour________his homework.
The weather is too dry.Those trees need________.
They had trouble________complete sentences.