完成句子（本大题共5小题，每小题2分，共10分）地面向下延伸，退落到下面的一条河里。
Far below me,the ground_____ _____ and down to a river.两年前，他放弃了教书，因为他太老了。
He______ ______ teaching two years ago because he was too old.每年都有数百万的人看莎士比亚的戏剧。
Shakespear’s plays are seen by_____ _____ people every year.当你有空的时候，给我发短信。
Send me______ ______ when you are free.你要确保在睡前关灯。
You must make sure you _____ _____the lights before you go to bed