The foreigners have been in Beijing for three years so they are familiar the city .A. toB

问题补充：

The foreigners have been in Beijing for three years, so they are familiar the city .

A. to

B. with

C. for

D. On

答案：

A. to

(答案→)B. with

C. for

D. On

解析：句意：那些外国人在北京呆了有三年了，所以他们对这个城市很熟悉，be familiar with sth意为“某人对什么熟悉”，而be familiar to后面常跟人，意为“某物为某人所熟悉、知晓”；故选B。