unclear

who is only twenty-nine与 why is it so unclear 是并列的特殊疑问句，所以用 is it

Exactly what he thought he would accomplish isunclear.他认为他到底要完成什么任务是不清楚的。

为您解答一，it是形式主语，真正主语是what...it二，what是形容词，定语，修饰force句子相当于a contract can have what force/ for people....it

是吗

It remains unclear whether he can help me.

It is still unclear ____ the little boy got the CD player to work.请问怎么选，考了哪些考点？A.where B.what C.that D.how选D此题考查由连接副词how连接宾语从句。因为It is still unclear“ 仍然不清楚”，就会想弄清楚他the little boy是【怎样how】使the CD player to work运作的，所以，选how。

因为它会有有害产物只要有就是unclear

回答：有区别，它们的 意思不一样：前者意思是：越来越不清晰；后者意思是：越来越清晰。less and less越来越不，unclear不清晰，否定之否定等于肯定。

你要问的是不是Precisely why this is so it is unclear but the shifts related with changes in hormones (荷尔蒙) at adolescence and the decline in those hormones as we age翻译：现在很清楚的是为什么荷尔蒙会跟随青春期变化而变化和随着年量的增长逐渐减少的答案依旧不清楚。

Clear 后不加er, 形式上可以，但口语上很少这么说，unclear 可用，obscure,indistictive,vague 替换。