問題詳情

48.______ much is known about what occurs during sleep, the precise function of sleep and its different stages remains largely in the realm of assumption.
(A) Because
(B) For
(C) Since
(D) While

參考答案

答案：D
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)