若工作时间是由三点估算法估算出来的，则线路时间为随机变量。（）
参考答案：对
Is this room ______ the meeting?[ ]
A. large enough to have
B. enough large to have
C. large enough having
D. enough large having
结扎输卵管能够避孕，原因是（ ）
A．使卵细胞不能受精
B．使卵细胞不能形成
C．使性激素不能分泌
D．以上都是
