You should understand the traffic rule by nowYou’ve had it ________ often enough

It is generally believed that teaching is _____ it is a science.

He told me his computer company was in great need of a capable leader, ______ with strong will as well as good humor

almon, disabled, is attended throughout her school days by a nurse _____________to guard her.

17．The movie is to deucate people about environmental problems ______our planet.