Session对象哪些情况下会失效?() ["客户端浏览器关闭","Session的存活周期变为无效","Session超时","调用了Session的destroy()"]
海关执行职务受到暴力抗拒时,执行有关任务的()应当予以协助。 ["公安机关","人民武装警察部队","检验检疫机构","人民检察院"]
下列属于上行信道的公共控制信道是哪个() ["SDCCH","FCH","RACH","PCH"]
氢气漏气储罐要妥善处理、修复()后再用。 ["检查","防腐","检验","批准"]
servlet的生命周期由它的3个方法来控制,它们是()。 ["init()","service()","destroy()","doGet()","doPost()"]
在什么情况下需要外接制动组件?