求助Lzm E 9－30

Salt deposits and moisture threaten to destory the MK excavation in P, the site of an ancient civilization that flourished at the same time as the civilations in the Nile delta.

答案是这个选项，

但是不应该写成 that flourished at the same time as the civilations  do吗？

为甚么这里 do 可以省去？是因为flourish 后面没有接宾语吗？

尽量补，补了不一定对，不补不一定错。