It has been 60 years the two countries established diplomatic ties.A. that B. after C. fr

问题补充：

It has been 60 years the two countries established diplomatic ties.

A. that

B. after

C. from

D. since

答案：

A. that

B. after

C. from

(答案→)D. since

解析：句型it is/has been +段时间+since“自从…以来多长时间”“自从这两个国家建立外交关系以来60年了”选D。