Question

12．森林有利于防止水土流失．
Forests help to keep waterfrom washingthe earth away．

Answer 1

分析 from washing．

解答 答案：from washing．表示阻止…不做某，结合keep用keep …from doing sth，水土流失用wash the earth away，故答案是from washing．

点评 keep （on）doing sth．，继续做某事；不停地做；反复做某事
To keep doing sth until you have been successful．也就是很多人都没有成功的根本原因吧．

keep sb．doing sth．使某人一直做某事．，让某人保持做某事
I keep my son doing homework every evening．

keep sb from doing 妨碍、防止某人做某事
We should keep children from playing games too much．我们应防止孩子们过份玩游戏．