问题
Great changes __ in the city in the past 20years, and a lot of factories ____.
A:have been taken place; have been set up
B:have taken place; have set up
C:have taken place; have been set up
D:were taken place; were set up
B:have taken place; have set up
C:have taken place; have been set up
D:were taken place; were set up
正确答案是：
