I’m new at the party and I don’t have a friend ____.

When you ______ the book please return it to the library on time.

The experiment has ________ the possibility of the existence of any life on that planet, but it does notmean there is no life on other planets.[ ]

_________children learn to be independent, ________ it is for their future.

ough his classmates are all ahead ofhim, he is studying very hard to _____ them.