单项选择题 图示电路，利用电源等效变换，计算ＡＢ间短路时的电流Ｉ＝？ A  A、 B、 C、 D、

未知题型 What is the author's attitude towards The Grand Prairie Area Demonstration Project?A.Be optimistic to support this project.B.Became an opponent to those gaining unfair wealth from this project.C.Be objective to treat this problem.D.Be indifferent to this issuE.

单项选择题 利用Navicate的生成的备份文件，可以利用mysqldump命令进行恢复。