问题描述：
there have been many changes --- in my hometown in the last ten yeas
a\ happen
b\ happened
c\ happening
d\ to happen
为什么答案选c
说明理由
a\ happen
b\ happened
c\ happening
d\ to happen
为什么答案选c
说明理由
问题解答：
我来补答展开全文阅读