He came all the way to China for learning it better _______ for making money.

A．other than

B．more than

C．better than

D．rather than

计算题：一个电感线圈，两端加100V直流电压U时，电流I为25A，两端加100V、50Hz交流电压时，流过的电流I2为20A，求该线圈的电阻值和电感量。