网络函数<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/058dbbb5ab294d2980b41cd68dc78e69.png" />，其相应的单位冲激响应<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/efd689742f00449b818fd884bf9fd2cf.png" />为（ ） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/571d5a5173d64731a7a1ed5c3ffaf403.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/b923d3ac7e9743c68ad701c170b784b4.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/d3c454406cd94e97a23806c9ba83d4e0.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/159fc59d34794c2b9f24f1ddbc368a14.png" />

横桥的特性是（ ） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/d9109b1706b24ebdaaa4fd2ade011f0b.png"> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/3e73caf4907c4732b31655818429fd1f.png"> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/22fe3c7df73445cdbc78681845eb442f.png"> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/dda726f3f23e497ea5706434c05ee729.png"> E: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/1e933a32e7764e73841cf6d1ad056e95.png">

时序逻辑电路如下图所示，其状态方程组是。（）<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/75fb6bc0f79d4332b5bdc69605562aba.png" > A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/5f963aec69ea48089a47d3cea9ec8f96.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/4a0262f12d584d86a85b3d0917a539aa.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/0733702e95cb4432b6847bfa287c88cc.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/b4619d1e5055487c984ea3b0b338ee02.png" >

图示单口网络相量模型的等效阻抗等于( )<img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/20721ffbb1d64ad29d5b9cc9c3e8c602.png" /> A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/a505e0c3f6c540dfa69303f1383bf5d4.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/658644cc34254a9bb00700b269a6de65.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/8f656c874947474889404774e2eaf5bc.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/6438ce35699e439d800b0a42dda62d29.png" />

用三线-八线译码器74LS138和辅助门电路实现逻辑函数<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/c871492b27384497a59d367211b93efb.png" >，应：（） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/37b75181b0ad4fba92ee10f87ffa0bbb.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/453b2c724d1d4d41898e10c9ba036a39.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/2c10ee737f77406fa0457e0f02318515.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/9cbe3266526b4e8eab204cf96440be55.png" >

动作电位的“全或无”特性是指同一细胞动作电位的幅度（ ） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/f675bb76841f4662ab626587508b1f13.png"> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/6ff2d28ebd8a463695c3160b4efeabc2.png"> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/9d76fe69b3624a44b217c76f1d0df90f.png"> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/97de0c7c4099476c92addbbd7d106fde.png">

下列几个方程，表示质点振动为“拍”现象的是：（） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/9667dbfe77314804a8c29f40c44cd0eb.png"> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/c7bc921fc7c04ce6832fea3a190e7d8d.png"> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/87e37e83ce244721905379b745be2bba.png"> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/026e1391030345459a10867db4150d25.png">

钢号Q345A中的345表示钢材的（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/af6807e52a454663a6eaf1728a03a050.png" >值 B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/3cf447dcca4b4032bf4df7ef7b7a8f7f.png" >值 C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/390a6cad6f4746668ba550f409ead899.png" >值 D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202003/f0782fccfc8047bb9aea1b0934a4dfed.png" >值

https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/6c268fc1a77f4e73bd209d5b86b8ae98.png

https://image.zhihuishu.com/zhs/onlineexam/ueditor/202003/8961d14854d348848440a27bf62c83ca.png