Some steps ______ to control the overuse of tourism resources, b

Some steps ______ to control the overuse of tourism resources, but more needs ______ and the sooner the better.
A、take, do
B、taken, done
C、has taken, has done
D、have been taken, to be done
【正确答案】：D
【题目解析】：“have been taken, to be done”。这句话的意思是：“已经采取了一些措施来控制旅游资源的过度使用，但还需要做更多的工作，而且越快越好。”