下列结论错误的是（ ） A: 有界数列必收敛 B: 收敛数列必有界 C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201806/89b95e21b5484b1eb47dcf978abe6f53.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201806/ee27693800bb4cd2ae76608436dea153.png" />

<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/2205d9f03e724a04b34f2f1045309079.png" />的幅频响应是，幅频响应是。 A: 1，<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/760d7fcc2f264ed1b10fb836cb48f565.png" /> B: -1，<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/21f685d2962e4b6993bfcaa513bdbf68.png" /> C: 2，<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/57267e995f86426899ce3cc0177a2343.png" /> D: 1，<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/ea8ba62853a94a15a5620c5165e3594a.png" />

设<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/bed4f91f4fec44358e1cad3163fc6b90.png" />是在区间<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/a58a11f71a434f2ab38a2f347802f010.png" />上的<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/a392447e03794318affaa2b03bb5967b.png" />的分段线性插值函数，以下条件不是<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/c00fe77a8291453a8cb2577eb68735ad.png" />必须满足的条件是________________. A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/cf6e811a4488413fae8f1839e4d098ea.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/bb93b2d7d02245878ec51e2986c97b5d.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/ec6692c00c2e49b6adbf9b0493638b81.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/214f277da4154f58a43751f80b09d959.png" />

LTI离散系统的差分方程为<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/eb2e05fecafa414e98c3ffaf0b435e82.png" />，当激励<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/f6bdc410c9fd42b8b8dd675197919ceb.png" />时，求零状态响应<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/12bfebbed6b14e298e09c4cb1940677b.png" /> A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/69fc6db7834143a292ce24d4829a06e6.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/f7af4326d64c44669cd0f0d4c7b23eb1.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/f929cab698bd4309a4649201e7f5604c.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/81108c43b5f2457291e3723cc96280e1.png" />

What are the comedies of Shakespeare? A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/1882addb95d34f3e877db8ec62e82507.png"/> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/4e230d2e03cc46c2b717155e90fdd081.png"/> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/7f4368645eff4e4b9ec89b237843dabd.png"/> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/5ccbfc9718084d318abfbbe254ae048b.png"/>