问题
选择题
Once a difficult and even dangerous place , Vietnam is now a friendly detestation that welcomes visitors from all over the world .
A．considered; visiting
B．considered; to visit
C．considering; visiting
D．considering; to visit
答案
答案：B
题目分析：考查状语从句的省略句和不定式：句意：虽然曾被认为不适宜旅游甚至危险，现在越南已是全世界游客的目的地。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，这句话完整的是Once vienam is considered a difficult and even dangerous place,可以省略主语和be动词，所以填considered，第二空是词组welcome sb to do sth欢迎某人做…，选B。
