Great changes __________ in my hometown since 1990.
A：have been taken place
B：have taken place
C：take place
D：had taken place
近年来，盐城市狠抓节能减排，严格落实 “关停不达标企业、改善生态环境”的专项行动计划，对此，下列评论最合适的是（ ）
