【单选题】When was the Fraunhofer Society founded? 查看材料
【单选题】When television was first (introduced), the extent to (that) it would (affect) society could not (have been foreseen).
【单选题】构成运输系统的要素主要有运输对象、运输工具和运输参与者,铁路机车属于 。
【多选题】以下关于分群抽样的描述,正确的是
A.
把总体区分为若干群体,再从中抽取一个或几个群体作为样本,进行随机调研的形式
B.
适合在总体数量较大,各群集中性、均匀性较好的情况下使用
【单选题】选择花青素含量高的鲜叶制绿茶,下列叙述不正确的是( )。
【单选题】When we see well, we do not think about our eyes very often. (79) It is only when we cannot see perfectly that we realize how important our eyes are. People who are nearsighted can only see things tha...
A.
only when we can see well
B.
only when we cannot see perfectly
C.
even if we can sec well
D.
only when we realize how important our eyes are
【单选题】粉末直接压片时,既可作填充剂,又可作粘合剂,还兼有良好崩解作用的辅料是( )