高一英语寒假作业

1.A lot of steps have been taken to prevent the pollution____the lakes and rivers clean.
A making B to make C to have made D having made
2.The pilot lost control with the military base,_____the plane crashed in the desert.
A by means of which B for which
C in case of which D as a result of which
3_____ different life today is from what it was twenty years ago!
A How B What C What a D How a
拜托各位大侠帮帮小女，望解释详细些，小女当感激不尽
能不能补充一下第一题的细节，为什么不用D，不是有prevent sb doing sth吗

高一寒假作业 高二英语寒假作业 寒假作业上一些高一英语问题 高一英语寒假作业~在线等（高分） 高一物理寒假作业 高一寒假政治作业 一道高一寒假作业 高一数学寒假作业--集合类 高一寒假地理作业!帮帮忙! 高一寒假地理作业!帮帮忙!哇