【单选题】What have anthropologists recently found?
A.
There are cultural anthropology and physical anthropology.
B.
There are three steps in the progress of human beings.
C.
There were more civilizations in Egypt than in parts of Asia.
D.
There is a longer history of human beings than it was thought before.
【多选题】洪水攻击主要分为ICMP、攻击3种类型。
【单选题】I have bough two ball pens , _______ writes well.
【单选题】对于系统的基本属性描述有误的是( )。
A.
系统的要素与要素之间一定存在着相互的作用和有机联系
【单选题】R、L串联交流电路中,若电源电压为10V,电感电压为8V,则电阻上的电压为( )。
【简答题】Recently I bought an ancient vase, _________ was very reasonable.
【单选题】若R为电阻,L为电感,则R/L的单位为( )