求下列序列的[tex=0.714x1.0]RRR4SYyCqv01G5bWEEMPdw==[/tex]变换和收敛域[tex=5.0x1.357]zHS6oHYoHDlX/ddqGjrrpA==[/tex]

已知极限则a=0,b=6（ ）https://image.zhihuishu.com/zhs/onlineexam/ueditor/201911/b97eda7869144de1b30a6b2cb3e0fdfc.png

在6/8拍子中，哪种记谱是规范的？（ ） A: <img src="https://image.zhihuishu.com/zhs/teacherExam_h5/COMMONUEDITOR/202104/1fa00e5363084599af58abfe32d10c81.png" /> B: <img src="https://image.zhihuishu.com/zhs/teacherExam_h5/COMMONUEDITOR/202104/c5c9c50ae1314ab2852159f18cdfc13c.png" /> C: <img src="https://image.zhihuishu.com/zhs/teacherExam_h5/COMMONUEDITOR/202104/2579da4b06c74d1da3717f6a6562e070.png" /> D: <img src="https://image.zhihuishu.com/zhs/teacherExam_h5/COMMONUEDITOR/202104/c548bd12f6d84b92b2964322fad7904e.png" />

序列<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/e1790a2df1984f8da7b286621e37686d.png" />的长度为4，序列<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/5bd332b1c2a443b6ad2642f7370c587d.png" />的长度为3，则它们线性卷积的长度和5点圆周卷积的长度分别是（ ）。 A: 7, 5 B: 5, 5 C: 6, 6 D: 6, 5

图6所示电路，容性器件的复阻抗，可表示为: (     ) .http://image.zhihuishu.com/zhs/onlineexam/ueditor/201804/67254d48a8b541de8bce159f020b0028.png

看懂空气过滤器装配图，回答问题：零件6的材料是 。http://image.zhihuishu.com/zhs/onlineexam/ueditor/201808/e08b6e64aa1a48389c8e1826588f4f84.png

在配离子中，形成体是 ，配位数为6。https://image.zhihuishu.com/zhs/onlineexam/ueditor/201909/41961a5feef0423188b8842a30a31dfd.png

下图中关于明度的9个等级中4、5、6为（）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/2b413aefcae7477c8a09afb64b0827fe.png

如图所示，结点1的结点电压方程为（ ）。<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201903/6eb9d76b79ce4dc5b16d961c3179a3ab.png" /> A: 6U1-U2=6 B: 5U1=6 C: 5U1=2 D: 6U1-2U2=2

下图关于纯度对比9调图，4、5、6对比表述为（）http://image.zhihuishu.com/zhs/onlineexam/ueditor/201902/6893c7bf37b9468dae8f58828e4da7d1.png