拆模时对养护工作有何要求？
（）是指一个配送模式可能出现几种结果，而又无法指导其概率时所进行的决策。 ["确定性决策","非确定性决策","收益型决策","风险型决策"]
西学专斋将二三十岁的学子，从（）等科学入门开始，培养国家急需人才。 ["A.英文字母","B.数学","C.法律","D.化学"]
The rated operating time of a self-contained breathing device may be reduced in actual use because of（）. ["pressure differences in the atmosphere","the length of the hose attached to the facepiece","the physical exertion of the person wearing the device","spaces containing poisonous vapor"]
山西大学堂西学专斋1907年进入兴盛时期，还开办（）三个专门科。 ["A.法律","B.工程科","C.矿学","D.格致"]
简述单纯型高热惊厥的特点。
