问题
选择题
It ’s our duty to_________people_________too many trees.
A．stop; cutting down
B．prevent, to cut down
C．keep; cutting down
D．make; cut down
答案
答案：A
stop/ prevent sb from doing sth,阻止某人做某事,from可省略。Keep sb from doing sth,from不可省。因此选A。