如何判断是of itself 还是 by itself?
问题描述：
如何判断是of itself 还是 by itself?
40.When I was about to go out,the door opened ___.
A.of itself B.by itself
C.oneself D.for itself
答
of itself 是自动的,自然而然的意思
by itself 是独自的,单独一个人的,要用在至少有生命力的东西才能用by itself.
所以这题选A