【判断题】已知一批正态分布但不确定其均值大小的随机数字,现需要检验其均值是否为某个值,则应采用单样本t检验;
【判断题】AgCl在水中溶解度很小,所以它的离子浓度也很小,说明AgCl是弱电解质。
【单选题】The prefix hemi- refers to_______.
【多选题】1964年第三届全国人民代表大会上,提出“在不太长的历史时期内,把我国建设成为一个具有( )的社会主义强国”。
【判断题】已知一批正态分布但不确定其均值大小的随机数字,现需要检验其均值是否为某个值,则应采用单样本F检验;
【判断题】已知一批正态分布但不确定其均值大小的随机数字,现需要检验其均值是否为某个值,则应采用两独立样本t检验;
【单选题】Bracken, a poisonous weed, is spreading and damaging much pastureland in the Northern Hemisphere. One potentially inexpensive and self-sustaining countermeasure is to introduce natural enemies of the ...
A.
That bracken in the Northern Hemisphere grows in approximately the same climates and soil conditions in which it grows in the Southern Hemisphere.
B.
That the released moths will feed on weeds other than bracken that are native to the Northern Hemisphere.
C.
That the livestock that will return to pastures now lost to bracken will develop immunities to the diseases caused by bracken.
D.
That the released moths will survive in sufficient numbers to build a population large enough to reduce bracken and retard its growth.
E.
That traditional methods of control, such as burning, cutting, and chemical spraying, will not become less expensive or labor-intensive than they are now.