80. Salt deposits and moisture threaten to destroy the Mohenjo-Daro excavation in Pakistan, the site of an ancient civilization [U]that flourished at the same time as the civilizations [/U]in the Nile delta and the river valleys of the Tigris and Euphrates.
(A) that flourished at the same time as the civilizations
答案是A，（其他错都明显），但想问，A中， "as the civilization"后面是不是该有个did。
