又一prep语法求教

winnielxx

243. (GWD-10-Q8)
Sulfur dioxide, a major contributor to acid rain, is an especially serious pollutant because it diminishes the respiratory system's ability to deal with all other pollutants.
A. an especially serious pollutant because it diminishes the respiratory system's ability to deal
B. an especially serious pollutant because of diminishing the respiratory system's capability of dealing
C. an especially serious pollutant because it diminishes the capability of the respiratory system in dealing
D. a specially serious pollutant because it diminishes the capability of the respiratory system to deal
E. a specially serious pollutant because of diminishing the respiratory system's ability to deal


答案是A,可是我觉得A不好，respiratory system's ability按理说应该不如the capability of the respiratory system吧，因为respiratory system无生命啊，所有格可以直接用’s吗？所以我选的D项~~可是~~可是~~答案为啥是A 啊？为啥？有同学帮忙解释下吗？