更正楼上答案如下：
Great changes have taken place in my hometown in the past few years.
= (There) have (been) great changes in my hometown in the past few years.
解释：改句采用there be句型的现在完成时结构：there have/has been.
因为changes是名词复数,所以用there have been...
但是该句型中的be动词（been）是不能没有的.