---He went to see the man who was in hospital yesterday..A. So we did B. So did weC. W

---He went to see the man who was in hospital yesterday.--- .
A. So we did
B. So did we
C. We did so
D. Did so we

A. So we did (答案→)B. So did weC. We did soD. Did so we解析：“so＋助动词（情态动词或连系动词）＋另一主语”，此句型是主谓倒装结构，可以表示前面的情况也适用于后者，使用该句型需要注意以几个方面的问题： 1．该句型只能用于肯定句，不能用于否定句：如果前句是否定句，则要用“neither ／nor ＋助动词＋主语”。 2．句型中的主语与上文中的主语是不同的两个主语3．句型中助动词，包括连系动词和情态动词的时态要和上句中谓语动词的时态相一致。句意：他昨天去看那个住院的人了。我们也去了。故选B。

就是这个解释