下列属于{100}晶面族的晶面有（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/0add32d287a940f69e91fbae943eee76.png"> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/13d75d49e079433096f649f812fc69a6.png"> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/98be2e9d508448e48e920a1a5444366c.png"> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/7e55102ed4254dd2ad54dd1c36e0dd2a.png">

计算根轨迹渐近线倾角的公式为（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/608af0d299964c8f8821188092a56985.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/61795bdbc94c4921a02437814d1c0e29.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/6742e5f09f104644a3cf9be07ba7bdbd.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/477de697b8804d4ab36159a175ed07d9.png" >

若某系统的传递函数为G（s）=<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/40cffec1140048fda668f02b2697bfb6.png" >，则相应的频率特性G（jω）为（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/b0edaaca759a4b96b2746d371ba37485.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/17d6f581231244c386888754b3bf178d.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/e5485f9797b64853b91ce68c4697ff2e.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/5330c18e71b94abdbeaeff937486d18a.png" >

设积分环节的传递函数为G(s)=<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/2428288e967b4a34ade338e5ea5c6ce0.png" >，则其频率特性幅值A(ω)=（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/33a8b22368e4429585bd402fd07fd717.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/492828f883b74680b8b22570ec3522cf.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/0f44b2548a3c424eaa326c2bf10bece6.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/b93eaefa6dd04794949e3987d24a0991.png" >

一盒产品中有<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/2cefaaf8bcb54c61977cecb4f0e40dea.png" >只正品，<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/65c8182d811f448784675cc993c132d2.png" >只次品，有放回地任取两次，第二次取到正品的概率为（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/73a908d0e00e4b44b0f7c78fe3c62154.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/f36521dfc9c64099b22f506146ac867d.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/4c42ae8aa5544a68a018618378bda287.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/201912/f7ca6abeab84438095bee512a092be80.png" >