题目

过平行六面体任意两条棱的中点作直线, 其中与平面平行的直线共有 (A)．4条              (B)．6条           (C)．8条             (D)．12条 答案：D ______ is known to us all , the old scientist,______ life was hard in the past, still works hard in his eighties.      A. It; whom          B.As; whom     C. As; whose          D. What; whom