问题补充：
Today the forests are getting fewer and fewer. We must down too many trees.
A. keep people from cutting
B. prevent people from cutting
C. stop people cutting
D. all the above
答案：
A. keep people from cutting
B. prevent people from cutting
C. stop people cutting
(答案→)D. all the above
解析：句意：今天，森林越来越少。我们必须阻止人们砍伐太多的树木。Keep sb from doing sth，prevent sb from doing sth，stop sb doing sth都译为：阻止某人做某事。所以选D。
