Measures _____to stop housing prices from rising too fast, but it remains to be seen whether they still work.

A．are taking

B．had been taken

C．have taken

D．are being taken

机坪保障作业人员发现（）应主动拾起，并放入垃圾桶里。

A、垃圾

B、废弃物

C、碎片

D、以上三项都是