Have you________ Betty yet?—Not really．She won’t forgive me for having told her lies．

‘t cold enough for there _____ afrost tonight, so I can leave Lim’s bike out safely

I don’t mind picking up your things from the store. _______, the walk will do me good.

We should protect the environment, for plenty of fresh air ________ to good health.

I try to understand ________ that prevents so many children from being happy, there seem to be three causes.