【简答题】一个函数的图象关于y轴成轴对称图形时,称该函数为偶函数,那么在下列四个函数①y=2x;②y=-3x-1;③ ;④ 中,偶函数是( )(填出所有偶函数的序号)。
【简答题】以同志为核心的党的第一代领导集体提出了( )总路线,创造性地完成了由( )革命向( )革命的转变,使中国进入了( )社会。
【多选题】成本按经济用途可以分为( )和( )两类。
【单选题】Which of the following statements is TRUE?
A.
The subjects in a cross-sectional research are not of the same age group.
B.
The methods of study in longitudinal research will not change over time.
C.
Longitudinal research is reliable only in seeking understandings of the effects of early experiences on later development.
D.
Cross-sectional methods are not usually adopted in studying, for example, the changes in intelligence over a thirty-year period.
【单选题】The optimum cross-sectional thickness for an elastomeric impression materials is( )
【单选题】Which of the following is NOT a characteristic of a cross-sectional study?
A.
It is conducted at only one point in time.
B.
It can be exploratory, descriptive, or explanatory.
C.
It concentrates on the changes that take place among a specific sample over a period of time.
D.
It provides a means for studying a large population at the same point in time.
E.
All of these choices are characteristics of the cross-sectional study.
【单选题】听力原文:M: Excuse me, madam. I'm a stranger here and I'm running low on gas, but I can't seem to find a service station anywhere around here. Could you be kind enough to direct me to the nearest one? W: ...
A.
He needs a gas station.
C.
He wants to go to the hospital.
D.
He lost the letter to be posted.