If you go to Xi’an you will find the palaces there more magnificent than commonly .A. sup

问题补充：

If you go to Xi’an, you will find the palaces there more magnificent than commonly .

A. supposing

B. supposed

C. to suppose

D. suppose

答案：

A. supposing

(答案→)B. supposed

C. to suppose

D. suppose

解析：句意：如果你去西安，你会发现那里的宫殿比普遍认为的更加辉煌。这里是比较状语的省略，完整的是you will find the palaces there more magnificent than they are commonly supposed，当主从句的主语一致的时候，可以省略从句的主语和be动词，所以选B。