有4个顶点，如何连接4个顶点所用的管道最短？( )。
A:
B:
C:
D:
A:
B:
C:
D:
举一反三
- 长方体一个顶点的三个侧面的面积分别是 <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/177f124c9d4844ee9cb80dbdfd1e53b2.png" />，则长方体的体积为（ ） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/cca69e5a182840899ed8c0ef411d6c15.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/598019215ddd499f952f644dc14ddb0b.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/f293e69522584f56b51e00d7c7210bec.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/9364d6fbc3864b29b430b272126f8119.png" />
- 森林救火模型中，队员人说x，损失费用<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/a7b3bb68726943bf850131151512da56.png" >表示，救援费用<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/10d199675f734d4492fbe27b528023f7.png" >表示，目标函数是:（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/af6eaeb0e41646759e07de5609baf6e2.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/eb052c5d448843d180f7e28d97ea2767.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/b5868eec78f94cf5a428f254e6195d8b.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/0203e76fa2424495a2072562b8173c3d.png" >
- 下列时间复杂度最好的是（）。 A: O<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/fa34894ec21a44e399feadbac71a8340.png" > B: O<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/525b0bb57bcb42cf9e998f6c6a933991.png" > C: O<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/80351fa4ddde48a997031c49dc07fa7f.png" > D: O<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/28bd9a50afb741ff8a4805c6d22066f0.png" >
- 用于计算生活垃圾产生量的公式是（ ） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/730728c6b86c45b48207637d9ddf3d55.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/a12b43de83f546fbb215621eef41e521.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/796bb7cad2e840a794ba56d31772ba6e.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/e5a15dd29d974749a8e7dd3b38415d18.png" />
- 非线性系统状态空间表达式的矢量矩阵形式为（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/18f8e73a712b40dfb70c1e2631d84c95.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/4bb2d001d15c40a8a300932d7ace7fee.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/8ec872bfb564441fb15ffd9d0478bd26.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202010/f4126bd26c18419b99c27f1a37ce32eb.png" />