下面的句子如何番哪个地方错了
问题描述：
下面的句子如何番哪个地方错了
exercies (in) conversation forms are important (for) foreign students(,so )they must understand what they (hear as) well sa what they read.
答
通过用外语交谈来训练外语对学习外语的学生来说十分重要,因为他们不但要会读,还要会听.
第三个空我认为应该是（,because)