• 2022-06-10 问题

    ${\bf P}(X=4)=\,$ ${\bf P}(X=3)=\,$ ${\bf P}(X=2)=\,$ ${\bf P}(X=1)=\,$______

    ${\bf P}(X=4)=\,$ ${\bf P}(X=3)=\,$ ${\bf P}(X=2)=\,$ ${\bf P}(X=1)=\,$______

  • 2022-06-01 问题

    设\( {\bf{A}} \) 为三阶矩阵,\( { { \bf{A}}^*} \)是\( {\bf{A}} \)的伴随矩阵,且\( \left| {\bf{A}} \right| = 1 \),则\( \left| {2 { { \bf{A}}^{ - 1}} + 3 { { \bf{A}}^*}} \right| = \)______

    设\( {\bf{A}} \) 为三阶矩阵,\( { { \bf{A}}^*} \)是\( {\bf{A}} \)的伴随矩阵,且\( \left| {\bf{A}} \right| = 1 \),则\( \left| {2 { { \bf{A}}^{ - 1}} + 3 { { \bf{A}}^*}} \right| = \)______

  • 2022-06-10 问题

    ${\rm var}(X)=\,$ ${\bf E}[X]=\,$ ${\bf P}(X=3)=\,$ ${\bf P}(X=-2)=\,$ ${\bf P}(X=1)=\,$ ${\bf P}(X=0)=\,$______

    ${\rm var}(X)=\,$ ${\bf E}[X]=\,$ ${\bf P}(X=3)=\,$ ${\bf P}(X=-2)=\,$ ${\bf P}(X=1)=\,$ ${\bf P}(X=0)=\,$______

  • 2022-06-19 问题

    background:url(2、png),url(1、jpg),url(3、png),url(4、jpg);},表示哪张图片处在最上层() A: 2、png B: 1、jpg C: 3、png D: 4、jpg

    background:url(2、png),url(1、jpg),url(3、png),url(4、jpg);},表示哪张图片处在最上层() A: 2、png B: 1、jpg C: 3、png D: 4、jpg

  • 2022-05-29 问题

    ED WEQWERQWRQWRQWR A: 1 B: 2 C: 3 D: 4

    ED WEQWERQWRQWRQWR A: 1 B: 2 C: 3 D: 4

  • 2022-07-23 问题

    下列各组化合物分子中,键角大小顺序正确的是()。 A: HgCl<sub>2</sub>>BF<sub>3</sub>=PH<sub>3</sub>>CH<sub>4</sub> B: CH<sub>4</sub>>PH<sub>3</sub>=BF<sub>3</sub>>HgCl<sub>2</sub> C: HgCl<sub>2</sub>>BF<sub>3</sub>>CH<sub>4</sub>>PH<sub>3</sub> D: PH<sub>3</sub>>CH<sub>4</sub>>HgCl<sub>2</sub>>BF<sub>3</sub>

    下列各组化合物分子中,键角大小顺序正确的是()。 A: HgCl<sub>2</sub>>BF<sub>3</sub>=PH<sub>3</sub>>CH<sub>4</sub> B: CH<sub>4</sub>>PH<sub>3</sub>=BF<sub>3</sub>>HgCl<sub>2</sub> C: HgCl<sub>2</sub>>BF<sub>3</sub>>CH<sub>4</sub>>PH<sub>3</sub> D: PH<sub>3</sub>>CH<sub>4</sub>>HgCl<sub>2</sub>>BF<sub>3</sub>

  • 2022-06-06 问题

    ask(ed) A: want(ed) B: pleas(ed) C: carri(ed) D: help(ed)

    ask(ed) A: want(ed) B: pleas(ed) C: carri(ed) D: help(ed)

  • 2022-07-23 问题

    下列各组化合物分子中,键角大小顺序正确的是 A: BeCl<sub>2</sub>&gt;BF<sub>3</sub>=NH<sub>3</sub>&gt;CH<sub>4</sub> B: NH3&gt;CH<sub>4</sub>&gt;BeCl<sub>2</sub>&gt;BF<sub>3</sub> C: CH<sub>4&gt;</sub>NH<sub>3</sub>=BF<sub>3</sub>&gt;BeCl<sub>2</sub> D: BeCl<sub>2</sub>&gt;BF<sub>3</sub>&gt;CH<sub>4</sub>&gt;NH<sub>3</sub>

    下列各组化合物分子中,键角大小顺序正确的是 A: BeCl<sub>2</sub>&gt;BF<sub>3</sub>=NH<sub>3</sub>&gt;CH<sub>4</sub> B: NH3&gt;CH<sub>4</sub>&gt;BeCl<sub>2</sub>&gt;BF<sub>3</sub> C: CH<sub>4&gt;</sub>NH<sub>3</sub>=BF<sub>3</sub>&gt;BeCl<sub>2</sub> D: BeCl<sub>2</sub>&gt;BF<sub>3</sub>&gt;CH<sub>4</sub>&gt;NH<sub>3</sub>

  • 2022-06-06 问题

    I got 1.bor(-ed, -ing) last time during the lection because the topic was totally not 2. interest(-ed, -ing) for me, it was honestly 3. tir(-ed, -ing) to be there for me.Where do you need an -ed prefix for adjectives here? A: 1,2 B: 3 C: 4 D: 1

    I got 1.bor(-ed, -ing) last time during the lection because the topic was totally not 2. interest(-ed, -ing) for me, it was honestly 3. tir(-ed, -ing) to be there for me.Where do you need an -ed prefix for adjectives here? A: 1,2 B: 3 C: 4 D: 1

  • 2022-05-27 问题

    可靠安全系数是指() A: LD/ED B: ED/LD C: LD/ED D: LD/ED E: ED/LD

    可靠安全系数是指() A: LD/ED B: ED/LD C: LD/ED D: LD/ED E: ED/LD

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