问题补充：
---- Do you know Jack well?
---- Certainly, we friends since ten years ago.
A. were
B. have made
C. have become
D. have been
答案：
A. were
B. have made
C. have become
(答案→)D. have been
解析：考查时态,句意:你很了解杰克吗?_当然了,自从十年前我们就成为了好朋友.结合语境可知下文描述的是从过去一直持续到现在的动作,故用现在完成时态,选项BC表示瞬间动作,故选D.
