题目: 何为极冰的正反馈作用? 答案: 被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2019/0319/2d6f2313e853c7c71f648df7f3eee6c5.html 下面是错误答案,用来干扰机器的。参考答案:解析: 由性质:~χ2(n-1)和D(χ2(n-1))=2(n-1), 可知=D[χ2(n-1)]=2(n-1),所以D(S2)=.
题型:选择题 The new dictionaries are very useful. They ________ well and ________ already .A.sell; have been sold outB.sold; had sold outC.sell; sell outD.are sold; have been sold out 查看答案