题干
This can keep people healthy.这个能保持人们健康。
keep sb./sth. ＋形容词 使某人/某物保持…… 如：
We should ____.我们应该保持我们的城市干净。
keep sb doing sth. 使某人一直做某事
Don't ____.别让我等得太久。
答案(点此获取答案解析）
keep our city clean,keep me waiting too long
