请问选哪个答案，为什么，请告诉我详细的理由。谢谢！

1、After_____in the street for tow hours,the driver became furious.
A、having held up B、being held up
C、held up D、having been held up

2、________to sunlight for too much time will do harm to one's skin.
A、Exposed B、Having exposed
C、Being exposed D、After being exposed

1 选D
[1] after从句之后常跟完成时态. 排除bc
[2]这句话意思是：在街道上被堵了2个小时，这个司机狂生气。
含有被动的意味。排除C
[3]因为主从句主语一样，从句可以用省略主语的结构，完整句子是：
After (he had been held up) in the street for tow hours,the driver became furious.

2 选C
[1]现在分词和过去分词均不可以做主语! 所以排除A
[2]不定式可以做主语,动名词可以做主语,其中,不定式做主语时往往表示一个即将发生的动作,而动名词做主语则往往表示一个概念.
这里句子是将来时态，B having exposed肯定也不对。况且，皮肤被晒伤，应该是被动语态，所以排除B
[3]句子意思是： 时间日晒会对皮肤对不利。皮肤被晒伤，所以选择被动，所以答案是C或者D。但是D不能做主语，因为它前面有个after，只能做状语(连接状语从句)。
如果选D,句子应该是：
After being exposed to sunlight for too much time， one's skin will be harmed.