大全562一个奇怪的问题

1.        One reason why more young people lose their virginity during the summer than at other times of the year undoubtedly is because school vacations give adolescents more free time.

(A) One reason why more young people lose their virginity during the summer than at other times of the year undoubtedly is because

(B) If young people lose their virginity more during the summer than other seasons, it is undoubtedly because

(C) One undoubtable reason that young people lose their virginity more during the summer than other times is

(D) One reason more young people lose their virginity during the summer than at other times of the year is undoubtedly that（D）

(E) Young people lose their virginity more often during the summer undoubtedly because, for one reason

D是正确答案,其他选项都有明显的错误,但是我总感觉D 中"one reason"和 后面的"more young..."中间没有任何词连接,比如"why"好像怪怪的,不知道是不是有什么我不知道的语法点在里面.

各位大虾帮帮忙呀!

reason后接的cl. that 往往可省..习惯用法

但 evidence, belief, fact , hypothesis that cl.     此时that 不可省...