_____is known to us all is that we should do as much as we can ______ stop the pollution of the environment.
China has hundreds of islands, ___________ is Taiwan Island.
You must have waited here for a long time ,___________you?
Nearly________ of the surface of our planet is covered by water.
It’s said that __________ is going to give us a lecture.
We had ___________ wonderful time_________the party_______ other day.