题目内容
（请给出正确答案）
[主观题]
No sooner had I closed the door than somebody started knocking ______ it.A．onB．withC．toD．f
No sooner had I closed the door than somebody started knocking ______ it.
A．on
B．with
C．to
D．for
如搜索结果不匹配，请 联系老师 获取答案
醌类化合物中只有对醌形式的是()
A、苯醌
B、菲醌
C、萘醌
D、蒽醌
E、蒽酮
