油码头离靠装卸船作业,所用防火防静电缆绳是()缆绳。
A、钢丝
B、棕麻
C、尼龙
D、纤维
参考答案:B
关于液体蒸发和沸腾,下列说法中不正确的是( )
A.蒸发和沸腾都属于汽化现象
B.蒸发和沸腾都要吸热
C.蒸发能在任何温度下发生,沸腾只在一定温度下发生
D.蒸发是在液体表面发生的汽化现象,沸腾是在液体内部发生的汽化现象
Had I known about this computer program, a huge amount of time and energy ________. [ ]
A. would have been saved
B. had been saved
C. must be saved
D. was saved