问2道英语语法题各位大侠好!请教各位两道英语语法题,问题如下：1、Investigators__into the fir

问2道英语语法题
各位大侠好!请教各位两道英语语法题,问题如下：
1、Investigators__into the fires at nine Baptist Churches in Alabama over the past week are hoping a handprint left on one church's front door may help catch the perpetrator.
A.looks B.looked C.look D.looking
①这一题中,正确答案选D,答案解析说looking是（Who） look的省略,可难道不应该是（Who are） looking的省略吗?
②这一题的主语是Investigators,主语的谓语是哪个啊?是……past week 后面的 are?还是……front door后面的may help?如何分辨出来的呢?
2、At the symposium,the Prime Minister said that the Korean economy is facing greater economic hardships nowadays due to external variables such as soaring international crude prices and the strenthening of the Korean won,__a prolonged increase in exports.
A.despite B.in spite of C.although D.though
这一题中正确答案是A,因为C是连词所以不对吗?什么情况下可以选C（前面没有“,”的情况下吗?）,感觉这两个词的意思一样,选哪个都对呃……
真心感谢各位大侠的帮助!谢谢!