If he to the teacher attentively in the past year, he the answer to the question now.
A. had listened; would know
B. listened; knew
C. listens; knew
D. has listened ;knows
网友回答
(答案→)A. had listened; would know
B. listened; knew
C. listens; knew
D. has listened ;knows
解析：
试题分析:考查混合型虚拟语气。句意：如果在过去的一年里他认真听老师讲课了，那么他现在就能够知道这个问题的答案了。从in the past year 判断前面条件状语从句是对过去进行假设，应该用过去完成时；而后面主句中的now则提示应该是对现在的虚拟，应该用would +动词原形，所以整个句子是混合型的虚拟语气，正确答案为A。