第26题: [简答题]Why are Register messages needed in PIM SM? 参考答案:Because the first hop router does not receive the join message, its outgoing interface list is empty. It is necessary to use unicast to send the register message to RP, waiting for the join message from RP.
第34题: [单项选择]儿童SLE肾损害的发生率为() A. 90%~100% B. 40%~500% C. 50%~80% D. 30%~40% E. 30%以下 参考答案:C 答案解析:与成人相比,儿童更易发生肾损害,有50%~80%的患儿存在肾受累,其中约22%,的病例发展为肾衰竭。
第35题: [单项选择]Before we install a new heating system we should be sure we cannot make ______use of the one we already have. A. efficiently B. efficiency C. efficient D. more efficiently 参考答案:C 答案解析:这句话的意思是说,在安装新的供暖装置之前,我们应该确保对现有设备不能再加以有效使用。空格处缺少形容词做use的定语,故选(C)。(A)efficiently副词,有 效地;(B)efficiency名
第36题: [单项选择]正常前列腺液的pH为( ) A. 4.5~5.2 B. 5.4~6.2 C. 6.3~6.5 D. 6.6~7.0 E. 7.2~7.8 参考答案:C