靠轴向力压缩封隔件，使封隔件直径变大实现密封叫（）封隔器。
A.自封式
B.压缩式
C.楔入式
D.扩张式
参考答案：B
Dickens' later works present a criticism of the more complicated ,and yet most fundamental social institutions and morals of the Victorian England. Which of the followings is among his later works
A. A Tale of Two Cities. B. Sketches by Boz.C. Hard Times. D. Villette.
仪表风系统在ON/OFF控制方式适用于（）用气
A、全气量供气
B、间歇性
C、排气压力
D、用量稳定
