OG11-107 新兵举手题问

107.
                    In his research paper, Dr. Frosh, medical director of the Payne Whitney Clinic, distinguishes mood swings, which may be violent without their being grounded in mental disease, from genuine manic‑depressive psychosis.

(A) mood swings, which may be violent without their being grounded in mental disease, from genuine manic-depressive psychosis

(B) mood swings, perhaps violent without being grounded in mental disease, and genuine manic-depressive psychosis

(C) between mood swings, which may be violent without being grounded in mental disease, and genuine manic-depressive psychosis

(D) between mood swings, perhaps violent without being grounded in mental disease, from genuine manic-depressive psychosis

(E) genuine manic-depressive psychosis and mood swings, which may be violent without being grounded in mental disease

最后的分歧点在A 和C之间，distinguishes between A and B;  distinguishes A from B 这两种用法应该都是对的，但是没有选A是因为  mood swings, which may be violent without their being grounded ……这里多了一个their，我只是觉得读得不顺口，有哪位高人指点一下，告诉我语法点的出处吧，不甚感激！！！！

清楚明白，谢谢！！

呵呵