[tex=27.143x1.286]OBUMfOercQJrsj6EGdHK7xgDVJ42rGc3zI1URhs/o8EuWLFOuymBvQudS7Nt65BqVJt66Uog2wMJ1OvW7i8gKA3bgePlGWTmAhsVCgMVCrIuFXYnLEwht9p2gXDBWFVw[/tex][tex=26.857x1.286]06uhSzgZ/Zwtmx5e+jBnd2RD4QYscYj3B9/onliTbRTXh4n43hOcURiiNq328DHeDmQt5TaDgHjrLwQXt9nVWGRV7rKti5GPTOIadoNowGwl3gnLBlPAUeGhMlASHIbK[/tex]

[tex=14.429x2.0]uinGfe37l0ovVLP80uQYC4a0/Lt11GEcEDgqxO56xTnJ2mXjUxr73OOivFaKvDq/GzG2uOG5DWdDn0Oe9rj65A==[/tex][tex=26.857x1.286]o3By/XFfDzm7GQy6IJNeqvjuVNzh49vVboXg9fJ5TyqAK6FNHZsG5AZr+VX6InvxejVEMWQPc6Q9JGRryivQc8BMGjnlg4oC+7xnIaNpCjiJPshQHHOp9IwGuXpkP9Ys[/tex][tex=33.714x1.286]yy0qdFE0T/3I8195+SbUcfRw1yOScdkpK6Kl1AOkyUR4mBv4+aZC9bLOUYbBiVUBeL+qw2FWN9VGflA/KA0/bpBdNBPZHNR9RuoYKX6HqFhSWHJPyl6jqb4sNi83SWYEe0ID+ALUNE5003cUtsm2sA==[/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

已知反应 [tex=26.857x1.286]Wm+iqgI0T/PTlAoRUdsx+zx3cL1vRO9yjEt8UkK+KLjx15hioujfL2DBv5iV0nhlu+7DsLnLF7Y7E+Qf6C2pPTBYnmFlosMaHfi6qSiR0tJHOd/3mdELDSOJ09fLeIUhBz6qPaS/5XVpFZwnn8X/ddbOScX7L1fGXdcnKy15m2k=[/tex],则反应[tex=12.071x1.286]HNM6qk2CsqqljdBWEPTYsvVVXgc13fFhZpsErQ2fjhLVALlgGl36WM8lSgfl/zP5[/tex]的[tex=7.857x1.429]Zgvck6R1LoNfDpBDhyADImKhADKKFkz5bgfESQWQmDUhHUsT/1dQO127qpwEoO2E[/tex][input=type:blank,size:4][/input] [tex=4.0x1.214]JyKKxYEH64BGjqEijrXkuqrVwbuOcLbaaRIxS2XNJwY=[/tex], [tex=11.357x1.429]7qOsBkh+6MFpkkdkp1E7QN4ki/LHZ+zKlCOQcu2X/p3v+F2AkpG8E8eQlCjOaHOzwcna0aABeTZIXk1+8rib+oKbUK3PFX1BCnPNUgtGL7I=[/tex][input=type:blank,size:4][/input][tex=4.0x1.214]JyKKxYEH64BGjqEijrXkugLnPSl4WgflSsevy0nYwRI=[/tex] 。

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)

以下谓词公式中，( )不是逻辑有效式。 A: ($x)(P(x)∧Q(x)) Þ ($x) P(x)∧($x) Q(x) B: ("x)(P(x)∧Q(x)) Þ ("x) P(x)∧("x) Q(x) C: ($x)(P(x)∧Q(x)) Û ($x) P(x)∧($x) Q(x) D: ("x)(P(x)∧Q(x)) Û ("x) P(x)∧("x) Q(x)