[tex=22.429x1.286]WRjmnG+axrvzWD2xjlINOYBdobeTA/GHMIZwolq6N7IUKVQLiiMhEQHacnztw2FSIIr6/Bv12UUd1VYyVNRG/kP8szvINIoNf0T35MH1n3E=[/tex]

[tex=28.071x1.286]T7qxR1jMzTADlnpyyqHvT6wG/A3VrL0iAAOEeZLBHj4g4/acOP/YIfvlEROXANw51KGJBld0zIPtsHU3HWjuWSugKwBRs/8PF+6gXThv3TAq5ZDTMPEn46Oxo4wuokJ0[/tex][tex=22.429x1.286]HgMhn+PRNCJAHTPsSu1L8HvlmzIPEjCGx36/xVr2h+bHy9YPTN3b7j8NkLdgOaxoBbmGz4eAXW6IWl5dWNWic0mKt00mNPMGhVEhqjaJ42Q=[/tex]

[tex=29.357x1.286]DE+GrFxiVsug1JeNNDjQnbQo62Tfoj52XpKB8wP708mPRYCOEEmmr/WnYbQawlv0GorVK1XlLG1cZ5NhLaoYZbIhUBvhLWA6n+1UOtnAWEw0Mizly+1gHokqAQd7aU7/ZH1vXP9flL9LybIoqQfE/Q==[/tex][tex=22.429x1.286]olKfnoq/8y48STkeZY/r9IigNvKH38SafvUZ1npiEuQ+fccpJpePzvtsSdbnqL/wmW+EJonli1PdKn6iENS0AZRwz2+JFoZP4Jeywdm3luZTI64AsV0X639pwDXY7d7r[/tex]

已知[tex=22.429x1.286]7UnnkkF63TEzgQgD31r+vj0jyNagoFgETPdVJ59ph4GTLlh/x5T7Qk2rAk+dTlQm61dpaaNLA9w+Zr6srm43UQWSAmo8p2x1mFBCnjAmxPq5h0ZuwbUjplPyP0/ux4dWZRTqp4YN9fjLudVAWPYXZg==[/tex], 试用相量法求[tex=2.714x1.286]9MVQP+YhvXBJRIFledMMy4bg7SAzoWjmqyu6NYtBZzE=[/tex]。

下列选项为某变速器一、二、三、四挡的传动比，则三挡的传动比为（）。 A: 0.969 B: 1.286 C: 1.944 D: 3.455

下列变量组（）是一个闭回路。 A: {x，x，x，x，x，x} B: {x，x，x，x，x} C: {x，x，x，x，x，x} D: {x，x，x，x，x，x}

以下谓词蕴含式正确的是（）: (∀x) (A(x)→B(x))=>( ∀x)A(x)→(∀x)B(x)|(∀x) (A(x)↔B(x))=>( ∀x)A(x)↔(∀x)B(x)|(∀x)A(x)∨(∀x)B(x)=>( ∀x) (A(x)∨B(x))|(∃x) (A(x)∧B(x))=>(∃x)A(x)∧(∃x)B(x)

以下谓词蕴含式正确的是（）: (?x) (A(x)→B(x))=>( ?x)A(x)→(?x)B(x)|(?x) (A(x)?B(x))=>( ?x)A(x)?(?x)B(x)|(?x)A(x)∨(?x)B(x)=>( ?x) (A(x)∨B(x))|(?x) (A(x)∧B(x))=>(?x)A(x)∧(?x)B(x)

下列式中错误的是： A: (∀x)(A(x)Úp(x)) Û (∀x)A(x)Ú (∀x)p(x) B: ($x)A(x) Ù p Û ($x)(A(x) Ù p ) C: (∀x)(A(x)ÚB(x)) Þ (∀x)A(x)Ú( ∀x)B(x) D: ($x)(A(x)ÙB(x)) Þ ($x)A(x)Ù( $x)B(x)

判断下列推证是否正确。 (∀x)(A(x)→B(x))⇔(∀x)(￢A(x)∨B(x)) ⇔(∀x)￢( A(x)∧￢B(x) ) ⇔￢(∃x) ( A(x)∧￢B(x) ) ⇔￢( (∃x)A(x)∧(∃x)￢B(x) ) ⇔￢(∃x)A(x)∨￢(∃x)￢B(x) ⇔￢(∃x)A(x)∨(∀x)B(x) ⇔(∃x)A(x)→(∀x)B(x)