Most whales must come up for air after several minutes, _______ a few can stay under water for an hour or more.
― It is reported that Americans eat too much protein each day. ―They eat ______as they actually need.
_______China’s first manned space flight took place?
—Come on, please give me some ideas about the project. —Sorry. With so much work _____ my mind, I almost break down.
Whoever has ____ sense knows that smoking is harmful to people' s health.
Not until the motorbike looked almost new repairing and cleaning it.