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【简答题】
全体正实数的集合 ,对加法和纯量乘法 构成 上的向量空间. 则 的负向量为________.
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皮皮学刷刷变学霸
举一反三
【单选题】Which of the following is true about the persistence method?
A.
The method will work well if weather conditions change greatly from day to day.
B.
It is the simplest and the best way of producing a forecast.
C.
It is impossible to use the method because weather condition changes constantly.
D.
The root of the frequent failure of the method is the assumption on which it is based.
【简答题】说明冷变形金属在加热过程中各阶段组织与性能的变化。