关于非谓语动词作定语的两道题B 183.How I regret the days __________ in doin

关于非谓语动词作定语的两道题
B 183.How I regret the days __________ in doing the useless work!
A.which wasted B.having been wasted C.which wasting D.having wasted
该句中的句子不是非限制性定语从句吗?限定了The days.那不是不能直接用-ing的完成时而得用从句吗?
C 7.This is one of the questions _______ at the meeting now.
A.to discuss B.to be discussed
C.being discussed D.discussed
为什么不能选B?将要被讨论的问题似乎也无大碍吧..难道就因为出现了now?
非谓语快把我弄晕了……