下列输入输出关系中，表示非线性、时不变系统的是（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/13190a4383d54997b48eeb58f38f436b.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/2f52d632a75e4c968d71b9986dbe5976.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/e6d430a49ebd45a4b379da4690afdd97.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/e958ba2576fb48b986d14359af116bce.png" />

过3个互异节点<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/c93daa18788043aeba0c4c8d19dc37b6.png" />做拉格朗日插值，关于拉格朗日插值基函数<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/8e5bcb2a9a9c444f8bc3ad4fbe221f53.png" />，下列说法正确的是（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/65e145e64f2a4189b72db6f72f7ba94f.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/854cbb8156c5467d87595bdd4c8e4baf.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/fd8f5422c04a4ddba89f2b32dd4509c8.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/1a0ef95dd38648768a995114ca9e4abe.png" />

以下列4个信号的拉普拉斯变换，不存在傅里叶变换的是( ) A: 1 B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/8851fc1d1d25423f99532d86a4ab00fc.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/0aebd05182244a7692c57e132a11aeeb.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/2c0c1185c38e4c119d3827ce6d608550.png" />

围棋盒子中有多粒黑子和白子，已知从中取出2粒都是黑子的概率为<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/5560fa100a334bb98e61bbdbc87f7dc8.png" />，都是白子的概率是<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/0dbeb6c482464298bc7a08c6c18a880b.png" />则从中任意取出2粒恰好是同一色的概率是（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/0dbeb6c482464298bc7a08c6c18a880b.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/5560fa100a334bb98e61bbdbc87f7dc8.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/2643cdf37f0242d185d3efb5321a3999.png" /> D: 1

跳水运动员在空中绕通过自身质心的水平轴转动。开始时通过收拢四肢实现团身，其转动惯量为<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/2fb4bf0e83154323887a46cf893ff802.png" />，角速度为<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/28bb2523387d45079825d628cea84395.png" />，然后保持其质心位置不变，通过四肢伸开实现展身，使其转动惯量增加为<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/50f64ae7946c4760ab03320f2239ce97.png" />，则此时她转动的角速度变为( ) A: <img src="https://image.zhihuishu.com/zhs/teacherExam_h5/COMMONUEDITOR/202106/2a237e74294245e4ac1629286dad2003.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/3024f3a4115a44a5acd16ad282b5d823.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/e772bc285e2a435da2519e55b2b3e960.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202106/c027656a0b4a43abbc030a5c1478105b.png" />