[tex=22.357x1.286]D5qN3iXALoY2vYda0RVwl1jPcEORnrkeAGo+6ONjKjlpW8uy1fzRp4UA3uR/ogdBIUDA1WlUHMTXDbpbVZeL9sFpPRscKeMtJ8XN1K1Paws=[/tex][tex=23.5x1.286]dmLWBh01QNxFG0yvXzzY3gA+5qn4xJUc/XfuB65CArdQwIl6DuscvzVbj53RTF/9AwiYpCsyfCWOkTDNCTFHNB5BUMfMsecla52vk2xudMk=[/tex]

[tex=22.357x1.286]xpSgy+eXXC0BScth9JINu2qIMi9KgiULfxK1mO4c/XFofEaziB/hSKVZot5cLaIob+iC85HpxdwD48rV90WRKVUKrVe/8XfhLgTmw3spw+8=[/tex][tex=28.571x1.286]ty13grNkN2851u9UsWN+rTD5vqywI7jtlFmUnkuzNKOf1i/srEI7cGLHg9np1WxvNWZaFcAhQVuLSANpVHTUZi1Di4jiH9E1n+QpP1hhcHW4HL00Tse+GEt0BgqU2NGIRU9IDMghXZqI8yRBMFggAg==[/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=24.429x1.286]WR1abBN6xzeq179Z1L8h35SArxASjLTnD8EUtMYwnT6aJRxxvvQ5i3LNK7JjwYf7/HPLcIfrD/eGOMH8OqklnRkhHo6J6E23EU1UEhx3xA5tHsnKWAM48xkmbJ1pa7CS[/tex][tex=42.714x1.286]SzvPTNi3IZjZdrnBPCbkm8BZcONR0USZv7YTsSW2C5OGFJ47Q5Kle8BRXaKDWksHzOfStFn3Cq8RckhjV5esB/B5Dqf9xcrPCOx+GvuYCmVCnsqvruZZ7/OB4vwE8pRGocmo8hNUsVqU0cnm8qxRhqyRTJvjcHX0v2zikFtPBlfkYLZPQTVbOeBdXEyDB16s[/tex][tex=22.357x1.286]so3Cmdu1AAVvXdaSZLdifep34tvzhItKWf/5HceNPLNyaWuTIuTW1LRCHoYgsJ9wqPvDegsmaiw0Is3e1usUYPTaeoVr6Vk8sJu8TDrzWFHs40SWHdixGnHo3QtBZ7SF[/tex][img=259x272]179d4a363fe884e.png[/img]

电路如题图所示, 已知[tex=22.357x1.286]vCfWijyaQygRCQj97+fRRfmsaJH+ixPOgq2eckjR/4j7zfktNlO2Cse/6WdJfEEC7+Y597vwIJf37zjiNyEuXzLPVMg/mO1B0lP688YDJEs=[/tex], 当[tex=2.143x1.286]5u+Kfi2y78D0EeH+RhjPUA==[/tex]时[tex=0.714x1.286]yQZEV57S9rHjYvgfJydTyg==[/tex]闭合后, 绘出[tex=2.071x1.286]jIVSgnSdUUmjFDCKs831VQ==[/tex]及[tex=1.786x1.286]zv9fg5x4fm8TMb5YEKrj4w==[/tex]变化规律曲线图。[img=394x278]17d37716e145157.png[/img]

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)