C.were首先前后时态要一致..people单复数同形.. 由so many也可以看出people是复数形式..be动词用复数.所以选C.were
C.were因为前文为went，前后句时态要保持一致。
C.“did”“went”提示用过去式，“so many people”提示用复数，因此选C
C,过去时
B.are
C.were
