什么是胀管工艺?
参考答案:
把管子插入要连接的管孔中,对管子进行冷态扩张,使管子与管孔间保持径向压力,实现两者紧密连接的冷作工艺过程。
Because of the nuclear crisis caused by the earthquake in Japan, many people lined up to buy salt ______ seeking protection from radiation.
A.in face of
B.in search of
C.in terms of
D.in hopes of
无菌包的有效期为多长时间