【简答题】One of the major differences between man and his closest living relative is,of course,that the chimpanzee has not developed the power of speech. Even the most intensive efforts to teach young chimps t...
【单选题】已知直线l:xtanα-y-3tanβ=0的斜率为2,在y轴上的截距为1,则tan(a+β)=( )
【判断题】当合同中对某一问题未作出规定时,应参照有关国际贸易惯例。 ( )
【单选题】To assess how well a student is performing relative to his or her own previous performance,a teacher would use_________ assessment.
【简答题】已知直线 l : x tan a - y -3tan β =0的斜率为2,在 y 轴上的截距为1,则tan( α + β )=________.
【判断题】对于多元线性回归模型 ,参数β的最小二乘估计为 ,则 是β的无偏估计。
【简答题】在飞行中,由于 航线上各点的指向与经线的夹角始终保持不变,因而有利于用磁罗盘保持飞机的航向。
【单选题】What is the main idea of the second paragraph?
A.
Some plants have relative immunity to a great many diseases, while others have a susceptibility to them.
B.
The tolerance of a particular plant changes as the growing conditions change.
C.
A blight killed virtually every chestnut tree in North American.
D.
A blight may be a national infection.