关于比较的一些问题

wyywing

1 It is as difficult to prevent crimes against property as those that are against a person.
 正确答案是: it is to prevent those against a
疑问: 根据解析, it is 是为了强调对比对象, 保证形式对称. 想问一下, 如果没有it is 这个选项还是对的么? 而且,还是不是很理解为什么可以补上it is啊!!!

2 Salt deposits and moisture threaten to destroy the Mohenjo-Daro excavation in Pakistan, the site of an ancient civilization that flourished at the same time as the civilizations in the Nile delta and the river valleys of the Tigris and Euphrates.
正确答案是原句.
疑问: 为什么the same as 后直接加名词而不用加did呢?

3 Last year, land values in most parts of the pinelands rose almost so fast, and in some parts even faster than what they did ouside the pinelands.
正确答案是as fast as, and in some parts event faster than, those
疑问: 为什么是those 而不用加did?

mongmong

http://forum.chasedream.com/GMAT_SC/thread-558845-1-1.html?postid=15096497&searchmode=TopicContent&searchtext=The%20site%20of%20an%20ancient%20ci