假定消费者收入为m，则对于C-D型效用函数<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/cad6801a0e644022b0c2fe95e8a19989.png">，最优选择满足（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/cdf29b903396427293c59cf0351953f4.png"> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/f72e0dd95fd74bcfb1d0ad01736f7efc.png"> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/898a974abc0042deb61446fbb7c0f44a.png"> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/9e2fdd685d034af19b433d9185e329e5.png">

采用基2时间抽取FFT算法计算<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/f67e1917247149b497ced3c3798bea9a.png" />点序列的DFT，以下（ ）流图是正确的。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/76a32272ec1c4ab7a7efff7430a72d78.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/5398db8fd5714235b18480d2d9d3cfae.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/79bb453e60504ef195ebe4368d76c8a5.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/d521c85331ce46948d059dd2875d17e7.png" />

如果一个氢原子的电离能是<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/4dcf071313154d0ea93225d9a406e985.png" />， 则一个<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/c89b325c3d164b7d9865e00605b006ca.png" /> 离子的电离能为（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/85d5e9042a93497abfa3bb96856e78d2.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/4dcf071313154d0ea93225d9a406e985.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/411f7e2e2ee84fe4982c3fad6b02ce4f.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/4da15d5c01a442eb9bcb6fc2fd30f12e.png" />

图示电路的戴维南等效电路的参数是：()<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/f5d7aa3fc999448ea403bd5116ee008d.png" > A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/777f5a9976174ad7a9e01b3c5734899e.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/1a62711e7171419084181651c195d6f7.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/1138bdbe38b645749caa3f5c7c1e5e8d.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/37958a932ee34853b15f8bb9c495cf32.png" >

已知主、俯视图，若将主视图改为半剖视图，正确的是（）。<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/e6416653b88a4158a0b1fa78a1b000d0.png" > A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/aa82277795e04524a4d095bfb86f4f36.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/bfa603b5c9924802a09b956f16ff13d6.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/fff8cbcbe2244549b64dfa0b0a28d974.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202008/56e50b15486c4d1cbc1076daf2f499fd.png" >