产程中下列哪项情况最易发生子宫破裂（）
A.软产道阻塞
B.胎儿脑积水
C.横位
D.额先露
E.高张性宫缩乏力
参考答案：C
-- I think we'll give Bob a ring.
-- We ______ . We have been out of touch with him for ages.
A．will
B．may
C．have to
D．ought to
汽轮机主蒸汽温度在10分钟内下降（）时应打闸停机。
A.40℃
B.50℃
C.60℃
D.66℃
