[tex=39.214x1.286]58O7ST/Tr2+7nDrPPtNG+VvRFA0uf251LuRxWeNnJGGCzFJjRLvmXuBQvpGGwbZHjxEE6awwEwTRR6INzYXp5DTIYW+oq4Y+iFBTHrrYcIa2QHvCPl9fwcuh8q6kUJlVXQt5EQbP1oks2jdB5xVhEx2JtFTTKU1NdGPdtpahOq8aqtCoVeH5xqig39lGJser[/tex][tex=31.214x1.286]MT53NumOzU4fkp/QbkvUBtR++vZZ1BnvKgh+KCISsUcZkmMYLspSK0FQRt7tRnrVKwAa2/y31BIltFrK+7jpBzjjetOdsgUxTFn9HaeDE/OGBss9qcurS7imNX2wIJzpfXI2QfIcccFt3oxQZ1u6UA==[/tex][tex=13.571x1.286]YcyPIPTmKIossUmgHQEnLV90l4obe9j1kxrQsY9SLZgLZff8HYTW79ernHbuqqR8[/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

[tex=30.0x1.286]FQxEBEG0D6DfBb1twoZj9/ZcOq2oaXz/DLy7+pHKTUAwn/Ga5KgfYD/zE0d+mIl9QxPkG4hkrgWzQxwd9ExDWYFED+voikyeRrohABC2H1trAzXuBmWy2imRXyNbPYr2qWP0/otxTsrJQuUlKD1yCQ==[/tex][tex=32.357x1.286]bszUkVnYt/KlqQT6Qsza6+7Bid6/4RqPQ7I/5NcSFrXSvlo46o1RUuVlmeKg3mhyslRoWDeyOGkSgNZHTVc9tCOP7ormnsh6zAUlShSjQ1MdNR2eEwXfuWxlrda4SAh4cmK6N/JTn74L0omN7YKI66TKuv+YsHy5Au0T6uY3TMk=[/tex][tex=31.214x1.286]2RXVnnzlegqQdNHdWyKgxqjslwdKU+69vUqst3zlIvMB65dyjH8y1bWBbMiAcHhQRwgP8CCDNWj3JZ5sYcob/cEC9Vda8hl4BaNEjID0h9ay0YUdSVnrtUeWFgRIFicIX41N5Cx3qqfv7f5m49JTVw==[/tex]

[tex=27.929x1.286]jQhy8LvfEMJOhtjQaVTBx7tciO7AEzk8lJZxS2LcRtDHNzYwDmNgASPHdoqZPCt0grwC3og7e5HIPNjNQr0vRerkdmLdPjdCy/oJc1blDOGhffUqmpnuAFXL5qeJwzAQHwL52pA4pVBeGqNWjpM2vw==[/tex][tex=30.571x1.286]KHoq0J4gzkfyzCA4shzy4rOdE4bU3uGc8gEwS26rCICpTUV/HaKzxGsf9pc8VY+Ofh08NdC1y92wLTwLOXeGVwO/KlhAkbkm4QeQ/d7d7PetfpwZ41Aoh0iSJaUqD0fqX0W/cyY2JHiAhahPyUKA5A==[/tex][tex=35.571x1.286]JekKkTbKlHwUmJAp+1lK0VUkV19vaAmSxiwzCRfohyjHXbp+sEamyeV9sji/CKc9EjiTCa8FPpFhX4TW8j5m/RrqFvuV2PiKs78TKXbL69UxrLdEV2UFuDjVgU11J34/Q5JHDvC31gxRGS44wcIOWQaBfSEHWxo2/ESC6AsUOQw=[/tex][tex=31.214x1.286]Oqu30Ns55sZxlcc9SAKrLP333mb1iRXspgw8X2HFoTiIL/9Uk92ohfhHESxeJyklqk9UM5J9OFfdtIENcfMoGthmy/OiKR26fXA6z3YI9AWUYASPUS1rXHPtOc6byr/vvl0cIEUU0bsx/bU4vMZcRA==[/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)