英语试题1.---The little girl is always _____like an angel.---tha

英语试题
1.---The little girl is always _____like an angel.
---that's why she looks so pretty.
A.worn B.dressed C.wearing D.dressing up
请问为什么不选B而选D?
请分析
2._____is known to us all is that the old scientist,_____life was hard in the past,still works hard in his eighties.
A.as,who B.what,whose C.it,whose
请问为什么选B不选C?
怎么把上面的改一下,就能用C?
不懂,能不能详细点