各位,帮忙解个题,说明一下原因.英语的,在问题补充了里.

各位,帮忙解个题,说明一下原因.英语的,在问题补充了里.
1,Dina ( ) for months to find a job as a waitress , finally took a position at a local advertising agency .
A struggling B struggled C having struggled D to struggle
答案是 C
为什么是这个,不明白,不是已经有took 了吗,那不就是代表是过去的过去吗!
2,Attention, coffee lovers ! we have for you ,the best coffee machine ( ) invented.
A ever B already C even D nowdays
答案是A ,我想知道为什么不选D 我理解的是咖啡壶已经被生产出来了啊!求高人解答