【单选题】原总体为正态,总体方差未知且样本容量小于30情况下的平均数抽样分布为()
【简答题】补全对话 A: What are you going to do after leaving school? B: I'm thinking about becoming a pilot. That way I would be able to travel. A: 1 B: Of course I do. I like to visit different places, make differ...
【简答题】I tried to fight against my desire to eat chocolate, but I couldn’t. (go against) →
【单选题】滚动轴承外圈与轴承箱的配合基准应是()。
【单选题】Vibrations in the ground are a poorly understood but probably widespread means of communication between animals. It seems unlikely that these animals could have detected seismic 'pre-shocks' that were...
A.
the world’s earthquake laboratories were not effective in detecting seismic 'pre-shocks'.
B.
seismic signaling was the major communication form. of many animal species.
C.
those animal species can feel and understand all kinds of vibrations.
D.
all storage animal behaviors can be explained by extra-sensory perception.
【判断题】总体正态分布,总体标准差未知,且为小样本,总体平均数的差异检验可以使用t检验,也可以使用Z检验。
【简答题】The soldiers tried their best and did what they could _______ against the flood. A.fight B.to fight C.fighting D.fought
【简答题】I tried to fight against my desire to eat chocolate, but I couldn’t. (go against) 改为:
【单选题】The two dogs started to fight, so we tried to _____ them.