Question

They ________ friends since they were in the university．

[　　]

A．

have made

B．

have turned

C．

have become

D．

have been

Answer 1

答案：D
解析：

make friends交朋友(动作)；be friends成为朋友(状态)。since主句的动词应该是延续动词。故选D项。