【单选题】No student______ go out of school for snacks during the break without the teacher’s permission.
【单选题】常用的摘要算法是MD4、MD5、SHA和SHA-1。OSPF的安全协议使用
【单选题】One of our rules is that every student ______wear school uniform while at school.
【单选题】How many crayons do you have? [ ]