问题
Great changes ______ in the past few years, and a lot of factories ________
A:had taken place; have been set up
B:have taken place; have been set up
C:took place; have set up
D:were taken place; were set up
B:have taken place; have been set up
C:took place; have set up
D:were taken place; were set up
正确答案是：
