问题
选择题
--Don't open the door, _______who knocks on it.
--No problem, mom. You've told me many times.
A. even though B. no matter C. instead of
答案
答案：B
题目分析： even though虽然，即使，no matter无论，instead of替换，代替。no matter who无论谁。句意：无论谁敲门，都不要开门。放心吧，妈妈，你已经告诉我很多次了。故选B。