Most students in our class can not answer this question,so it should be\is very difficult.
问题描述:
Most students in our class can not answer this question,so it should be\is very difficult.
答
选be
答
Most students in our class can not answer this question, so it should be very difficult.
答
be
should 后加动词原形
be 是原形 is 是第三人称单数形式