设<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/995e39f9a3eb4d63889fb16f7a71ab39.png" />此复合函数由（ ）简单函数复合而成。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/c05e1e0bb27a44ea9923d749b2a7590d.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/7f6ba3596d1d4a3a8fe2bccb09ef5923.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/47a1f97cbc454d3dad189540f3ae1209.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/61c1ed05a21b47528fcebcfe7ffe85f9.png" />

下列方程中有一个是偏微分方程，它是（） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/5dda124ea27f4ab08181f464558054d5.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/548cc47b2b2f49989f36b9507bfd4589.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/218ee46dfbd048c2b57cd983a0814ad9.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/f034fb5c91bf48d4b8543c5f5e7058e1.png" >

下列式子中，正确的是（）。 A: A+A=A B: A<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/f3126967d9ec4564a40eb6115699ae51.png" >1=<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/0faff7be16814509823804103e6ad7d5.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/5cc39d909e9841baa3de9661f7c75548.png" > D: A<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/f3126967d9ec4564a40eb6115699ae51.png" >0=A

和逻辑式<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/6e44002682ae467796cf764f95bddba9.png" >表示不同逻辑关系的逻辑式是（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/2ed596686e0b4888be3e30cf991d4790.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/106e515ddf2e4efaaadb70de431d11ca.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/61241e1bfc1a46c6bf504129ed8c500d.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/b6133dc7cf894cc586f45f7a945b8325.png" >

下列运算正确的是（）. A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/b365f98671664fe28462e7f104a04561.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/4b0c61e395884131b3bd01a42cf554f2.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/40f0e907cde84b76bb93fce803d3960c.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202009/ce3ec94698c242069f90ba8debd032db.png" >