1. During the 1980’s approximately $50 billion in private investment capital is estimated to have left Mexico and added to the strain on the country’s debt-ridden economy.

(A) During the 1980’s approximately $50 billion in private investment capital is estimated to have left Mexico and added

(B) During the 1980’s it is estimated that approximately $50 billion in private investment capital left Mexico and added

(C) It is estimated that there was approximately $50 billion in private investment capital that left Mexico during the 1980’s and added

(D) It is estimated that during the 1980’s approximately $50 billion in private investment capital left Mexico, adding

(E) Approximately $50 billion in private investment capital is estimated as having left Mexico during the 1980’s, adding

答案 [D]

问题:1. B和D 中during的位置不同,意思有不一样么? "在1980期间,据估计..." "据估计,在1980期间"

2. D中, adding是否有修饰Mexico的可能?我一开始凭这个就排除这个选项了. 句子, doing(句末) doing可以做什么成分啊?

先谢谢大家指点了