按照方案二的效率指标计算，车公里产量为（）吨公里/车公里。 A: 2.758 B: 2.891 C: 4.125 D: 5.214

设二阶实对称矩阵[tex=0.786x1.0]b4HkKtHXeHofHX/gJc8Agg==[/tex] 的特征值为 1,2 . 对应于特征值 1 的特征向量为[tex=5.143x1.5]BbTTUs6j8FKcVjWPt3C+ufu8qhnBlnyG4e9wZOYuy0sxyt3pIObXPyVJCasI51Dg[/tex], 则矩阵[tex=1.714x1.0]+HNIZcMaSzNwCe0LO7bsUkDp++FgyT/wO++WJ584NNQ=[/tex] 未知类型：{'options': ['[tex=5.786x5.214]jcCMHflCR8OS9TosV6N5vJDJy76dqVqHyRD6PHOLS4iSOQchjOV4hJCZn0Bbzuhuf884Q3Zs5ZaWY4gPi/I4U28tLPv450h4bM38nl6azHl8el+nQ6yzzcn3tiw3VlDc[/tex]', '[tex=5.286x5.214]jcCMHflCR8OS9TosV6N5vIAPNau1G8ywhOUp6T3JQe+b+C+TT2umkvoNG+72kfKSd3zUy/KwT/L7QOuAF0fknHfhQ5fNPqeSxgolC+E5MtIA9XKReux7gWrUtwI+M1Kf7Rlh4vP4dFvR1X/LExq6PA==[/tex]', '[tex=5.286x5.214]jcCMHflCR8OS9TosV6N5vIAPNau1G8ywhOUp6T3JQe+b+C+TT2umkvoNG+72kfKSd3zUy/KwT/L7QOuAF0fknO+r3I3BuyYiX+xfM1lsR4SHEjensVUgPFS+t1FHTXGOYxB3r47xNZsW/GlMMgUQwQ==[/tex]', '[tex=7.143x5.214]jcCMHflCR8OS9TosV6N5vC+6CL9GbMrXfjBEZyw4MvTePoDYN8YhijmaAuv8SpV5nZ0swHEwilkFdzDWlsnEnaxAWVSoTYUUKbluwe9gFs6xLW12wIy7zbKyJ2Nx/aUM6Q5nxLMhAvdC+HL901eJNg==[/tex]'], 'type': 102}

设二阶实对称矩阵[tex=0.786x1.0]b4HkKtHXeHofHX/gJc8Agg==[/tex] 的特征值为 1,2 . 对应于特征值 1 的特征向量为[tex=5.143x1.5]BbTTUs6j8FKcVjWPt3C+ufu8qhnBlnyG4e9wZOYuy0sxyt3pIObXPyVJCasI51Dg[/tex], 则矩阵[tex=1.714x1.0]+HNIZcMaSzNwCe0LO7bsUkDp++FgyT/wO++WJ584NNQ=[/tex] 未知类型：{'options': ['[tex=5.786x5.214]jcCMHflCR8OS9TosV6N5vJDJy76dqVqHyRD6PHOLS4iSOQchjOV4hJCZn0Bbzuhuf884Q3Zs5ZaWY4gPi/I4U28tLPv450h4bM38nl6azHl8el+nQ6yzzcn3tiw3VlDc[/tex]', '[tex=5.286x5.214]jcCMHflCR8OS9TosV6N5vIAPNau1G8ywhOUp6T3JQe+b+C+TT2umkvoNG+72kfKSd3zUy/KwT/L7QOuAF0fknHfhQ5fNPqeSxgolC+E5MtIA9XKReux7gWrUtwI+M1Kf7Rlh4vP4dFvR1X/LExq6PA==[/tex]', '[tex=5.286x5.214]jcCMHflCR8OS9TosV6N5vIAPNau1G8ywhOUp6T3JQe+b+C+TT2umkvoNG+72kfKSd3zUy/KwT/L7QOuAF0fknO+r3I3BuyYiX+xfM1lsR4SHEjensVUgPFS+t1FHTXGOYxB3r47xNZsW/GlMMgUQwQ==[/tex]', '[tex=7.143x5.214]jcCMHflCR8OS9TosV6N5vC+6CL9GbMrXfjBEZyw4MvTePoDYN8YhijmaAuv8SpV5nZ0swHEwilkFdzDWlsnEnaxAWVSoTYUUKbluwe9gFs6xLW12wIy7zbKyJ2Nx/aUM6Q5nxLMhAvdC+HL901eJNg==[/tex]'], 'type': 102}

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)

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