A:
B:
C:
D:
举一反三
- 下列信号中，____是能量信号。 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/e8fc82c3d7b046fc949119acef31f0f0.png"> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/6085f08fa59b45e0ac501f77d9e9ac5c.png"> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/450d1385152b4c67a5ec0e2e7a8f50d7.png"> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/7a668260d2ea405ea903fc344f3ea5bc.png">
- 下列信号中，______是因果信号。 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/56c3db40bb36428688799a6164924c2b.png"> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/c775ed12f5af47549261ce4b9ae7c969.png"> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/1a1575aacbdf4e95882a87cf2a5a7049.png"> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/48b1a932dc504373ab3bf0e87edb513a.png">
- 下列信号中，哪一个是非周期信号？ A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/83f68e76be124295b0983618abb2469a.png"> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/0d9998b227e44cf9923532daf025311e.png"> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/a67487615b1248bd9a7978fa581f8821.png"> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/14e55c6393c74631a39866e1b8befc89.png">
- 读装配图中零件10，下列哪个图是正确的 （ ）<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/3e06ba277c804a0184232a92dc4daae8.png"/> A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/f552fe75449e4a54ac92d376ccb56c4d.png"/> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/ceee8794adba4c09a22636cc1400760a.png"/> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/de760892beba4aa0b43f5ad85fa1a8e3.png"/> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/bd80973d489b4003904efdee208828b2.png"/> E: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/3206dcc5d56c4536b359f5b66ae1fe03.png"/>
- 下列系统中，_______是线性的。 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/69188060fb4c48d68700d5224ce70e53.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/66e06f948fa34740a90a8c1cc227c6b6.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/4c264641de7b410e873171e90fd444ef.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/a3f710b25c2248b48ed5f6f1d342c078.png" />
内容
- 0
电子显微镜的分辨率可达到在（） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/41606c058d104fe3a157df1c821c6950.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/df2b0f80acc349779789c6d508af4e3d.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/6863b36a8c7e452a8668a5dacff64282.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/6fb394a51b584fc3a9db13fa9c5a7299.png" />
- 1
下面哪一个必定是错误的（ ） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/ec78b3caad34427297f9ecfdaafbefff.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/2ed85e95d14c40c3b73214e3a200746a.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/aed12e27a9934e6da5aa4b97f47786d6.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/c82a69a1467d423caa27e593e84c9bad.png" />
- 2
下列哪种情况属于存在序列相关 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/7677353003d1437481e2ce756c2ca461.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/e1c5942e7b8f4e3688783b6ad39f04cd.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/3d41ccb91db349c3b684656f44e58cb9.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/c948f65d5ab942b2abbf34bf5e141e26.png" />
- 3
函数Y=AB+AC的最小项表达式为: （ ） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/513c2f01af7d407daa80adcc252243b0.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/2a22507a9a71450db4763f911c8da08a.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/3112343cb6d44720a379a8fd1903c29e.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/62420a24b7374ebd9169f3ad94897f4a.png" />
- 4
下列卤代烃中哪些不能用于制备格氏试剂 A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/8e4b1eddb7974957a9ea3b2108b82f94.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/0b5b9f82a0f240448d093df7d3f2f47a.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/f0972e4286ca44a3b598a774bd2ece7c.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/201912/71069a506c07480bb0e9b25b1c7e015d.png" />