三道英语题,高三,求详解!some green beans,____ long enough,can be poison

三道英语题,高三,求详解!
some green beans,____ long enough,can be poisonous
a.if not to be cooked b.if not cooked c.if not cooking d.if not being cooked
ps:上课老师说了时间状语,原因状语可用分词表被动什么的是什么意思?
there were many guests at the party yesterday.l looked for two seats to sit down with my friend but found_______
a.neither b.nothing c.none d.no
ps:我选的是c
______employees feel about work, their primary motivation to work is to earn a living
a.whenever b.no matter what c.whatever d.no matter how
ps:这几个选项有什么区别呀
第一题我不确定老师是不是怎么说的,但就是类似的知识点
各位能解释的详细点咩,理解不了啊
还有第二题答案是c,打错了,我原来选的b