以下哪个家具是衣架。
A:
B:
C:
D:
A:
B:
C:
D:
举一反三
- 设二极管的端电压为U，则二极管的电流方程为（ ） 。 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/8fc1bd7f467e423a9abedfbcf36b63bf.png"> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/96c0065cd93f445abe2243c79b5a11f5.png"> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/e7babcc7dd7c478bbabd8438754ba07b.png"> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/dc06cb808c2a4d20b75fa70ba39feefe.png">
- 给定下述系统的差分方程，则__是非因果系统。 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/df1ece1947ea4ec394f9801bb6a8623e.png"> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/4963ffe14fd64ba983b60ad14bd498e2.png"> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/3c6bc338aedb4d04baa637de5d7d9506.png"> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/53dbdd529a5443188250b588e1de8d36.png">
- 以下四个图所示的力三角形，哪一个图表示力矢R是F<sub>1</sub>和F<sub>2</sub>两力矢的合力矢量 （ ） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/e5882668f0e84059a814aa855a51c3f6.png"/> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/7ce37cfeee134a2a8e6cef983a8c334e.png"/> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/3c0b7ba6eaa14d0597864d403938923d.png"/> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/bd13812c38674e828a05477ef3fa6c61.png"/>
- 系统用差分方程描述如下，x(n)和y(n)分别表示系统输入和输出，则____是非线性系统。 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/badc151a5233411b811be09f97702c35.png"> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/def3a29458ab40a787b81bb9f6656d24.png"> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/8323ed0bbbb04ca6a10de2be706bbf3f.png"> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202006/525c5c85f7ff4ab690f3bade6212d4e6.png">
- 如图所示电路的逻辑表达式F=（ ）。<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/8655693a417e4e43a32e0732ed533c96.png" /> A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/beda73211aea49f082d9137fd4eb0526.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/7388c99ee0824f20bcf85893934a2f6a.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/9a5c81e78b344c79a9389e932a7f55ce.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/82193a9a030243728012b02e15718987.png" />