1mol双原子理想气体在恒容下温度升高1K，过程的ΔH=（）J。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202001/6a55e7329aa147e49cfac2c88996a427.png"> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202001/63a0b426235344bc91251f4df9696391.png"> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202001/0b32631154e24f89940447ef4f3477f5.png"> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202001/e0d9cb5e46eb41a6b04799265a3bc82b.png">

在一定温度、压力下，对于只有体积功的任一化学反应，能用于判断其反应方向的是（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202001/d7e23d8a51cc40208278036cd4680ae6.png"/> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202001/61caacea700541969943f299b3161471.png"/> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202001/be92da656fa34305a8b083115cd9c1c3.png"/> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202001/ba3dab27f5fe49a48fc9eff148ab575e.png"/>

已知f(k)的z变换<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202105/fcb29424b0f74f9d8bf5e13ec738f383.png" />，F(z)的收敛域为下面哪一项时，f(k)为因果序列 ( )。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202105/a75ad7c5eb8849f6a24916fc871c1739.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202105/3e62806a63e74e78bb29212d2a5bef0a.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202105/25250b041bec4d5093675240862554e4.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202105/2eae229138be4af5a084d0996e2d57d2.png" />

已知 f (t)，为求<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/1fb776d0006a4eb2b93e07afcad58896.png" />则下列运算正确的是（其中<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/ada31d4207fe47d4908574b0a478486b.png" />， a 为正数）（ ） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/fb0a09472a6b4408b3e833c2568308db.png" />左移<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/ada31d4207fe47d4908574b0a478486b.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/fb0a09472a6b4408b3e833c2568308db.png" />右移 C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/06dbb96ce1044280b13167a33033e4c6.png" />左移<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/ada31d4207fe47d4908574b0a478486b.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202101/06dbb96ce1044280b13167a33033e4c6.png" />右移

下列各组中哪两个音之间为自然全音（ ） A: B——<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202104/2141580b985544a086e54a919153ac07.png" />D B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202104/2141580b985544a086e54a919153ac07.png" />E——<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202104/eb254aec548342c5bb15b15aae65aaf6.png" />F C: B——<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202104/eb254aec548342c5bb15b15aae65aaf6.png" />C D: A——<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202104/2141580b985544a086e54a919153ac07.png" />B