27. In 1929 relatively small declines in the market ruined many speculators having bought on margin; they had to sell, and their selling pushed other investors to the brink. (A) speculators having bought on margin; they had to sell, and (B) speculators who had bought on margin; having had to sell, (C) speculators who had bought on margin; they had to sell, and (D) speculators, those who had bought on margin; these speculators had to sell, and（C） (E) speculators, who, having bought on margin and having to sell, a不是更简洁么 [em06] | 
