I don’t understand ______ such a silly question in class yesterday.
_____ are you staying in Tibet? — Just for four days. [ ]
Doing exercise for _________ hour every day is good for our health.
Where is your English teacher? I’m looking for him everywhere.—He _____ the Internet in the computer room.
_______,parents should spend as much time as they can________with their children,thus they can influence them on the value of life.