单选题 较易0.85 引用2 组卷328
下列各命题中正确的命题是
①“若
都是奇数,则
是偶数”的逆否命题是“若
不是偶数,则
都不是奇数”;
② 命题 “
”的否定是“
” ;
③ “函数
的最小正周期为
” 是“
”的必要不充分条件;
④“平面向量
与
的夹角是钝角”的充分必要条件是“
” .
①“若
![](https://img.xkw.com/dksih/QBM/2013/2/22/1571117392699392/1571117397884928/STEM/2d2f363c9a49457caf743265e1fb2e31.png)
![](https://img.xkw.com/dksih/QBM/2013/2/22/1571117392699392/1571117397884928/STEM/ad4f83405fed4139b834c723d02bc9fa.png)
![](https://img.xkw.com/dksih/QBM/2013/2/22/1571117392699392/1571117397884928/STEM/ad4f83405fed4139b834c723d02bc9fa.png)
![](https://img.xkw.com/dksih/QBM/2013/2/22/1571117392699392/1571117397884928/STEM/2d2f363c9a49457caf743265e1fb2e31.png)
② 命题 “
![](https://img.xkw.com/dksih/QBM/2013/2/22/1571117392699392/1571117397884928/STEM/c7703cfe40a8401ba99ac88da8cb5c2f.png)
![](https://img.xkw.com/dksih/QBM/2013/2/22/1571117392699392/1571117397884928/STEM/1a0c5d074298462081e0cdbd6b61b09c.png)
③ “函数
![](https://img.xkw.com/dksih/QBM/2013/2/22/1571117392699392/1571117397884928/STEM/5a06f802c0b84ca6bc25c9c4ac82d4d2.png)
![](https://img.xkw.com/dksih/QBM/2013/2/22/1571117392699392/1571117397884928/STEM/f0a22d9f4acd464fac05a3a9e8267cf4.png)
![](https://img.xkw.com/dksih/QBM/2013/2/22/1571117392699392/1571117397884928/STEM/f0ab7d52da9e459fa3d4fba4fb516a41.png)
④“平面向量
![](https://img.xkw.com/dksih/QBM/2013/2/22/1571117392699392/1571117397884928/STEM/f89df65acb604edab5804c37c906bbd3.png)
![](https://img.xkw.com/dksih/QBM/2013/2/22/1571117392699392/1571117397884928/STEM/e68460ead46e4a72b8d8072fc33e1001.png)
![](https://img.xkw.com/dksih/QBM/2013/2/22/1571117392699392/1571117397884928/STEM/f4f679e527244dbdbf83b36c499a06fa.png)
A.②③ | B.①②③ | C.①②④ | D.③④ |
2012·山西·模拟预测
类题推荐
下列说法正确的是( )
A.集合 |
B.“ |
C.命题“若 |
D.命题“若 |
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