婴儿腹泻重度脱水，累积丢失补充液量是
A．50mlB．50～80mlC．50～100mlD．100～120mlE．80～120ml
参考答案：D
Was it _____ he was playing volleyball on the playground _____ he got hurt? [ ]
A. that; when
B. when; that
C. that; where
D. where; that
石英系列光纤的工作波长不能超过（）μm。
A.1.55
B.2
C.2.3
D.2.5
