27. Obtaining an investment-grade rating will keep the county's future borrowing costs low, protect its already-tattered image, and increase its ability to buy insurance. A. Obtaining an investment -grade rating will keep the county's future borrowing costs low, protect B. To obtain an investment-grade rating will keep the county's future borrowing costs low, and protect C.Having obtained an investment-grade rating will, in keeping the county's future borrowing costs low, protect D.To obtain an investment-grade rating would keep the county's future borrowing costs low, protecting E.Obtaining an investment-grade rating,keeping the county's future borrowing costs low, would be protecting
求大侠指教,为什么不可以选B,答案说天哦obtain是an objective in and of itself, not a means to achieve the desired benefits.为什么?不明白OG上的解释?
我还想问的就是,D选项,OG的解释是: protecting introduces an adjective phrase describing the subject of the sentence, but this makes increase into a verb with no subject. 为什么protecting令increase没有了主语?