【单选题】What is the main theme of the passage?
A.
Having a goal is vital to success.
B.
Being good is different from being great.
C.
One cannot succeed without time and practice.
D.
Luck,talent and family help to achieve success.
【单选题】According to the Production Manager, what is the main reason for the success of Lifestyle. Foods?
【单选题】Simens' success mainly comes from
【简答题】为防止因高压侧单相接地故障而引起低压侧的电压升高,自耦变压器的中性点必须可靠的()。
【单选题】在由三个相同阻值的电阻组成的先串联后并联的电路中,串联支路的电流比另一个支路的电流()。
【简答题】串联电路中电阻的()值相同,并联电路中电阻的()值相同。
【多选题】如果变压器的二次线圈的输出电压有效值是U2,则桥式整流电路中关于二极管型号选择正确是()
A.
最大正向电流不能小于0.45U2/RL,工程上一般会按照2-3倍选择更合适
B.
最大正向电流不能小于1.1*(0.45U2/RL),工程上一般会按照2-3倍选择更合适
C.
最大反向耐压值不能小于1.1*U2,工程上一般会按照2-3倍选择更合适
D.
最大反向耐压值不能小于1.1*1.414*U2,工程上一般会按照2-3倍选择更合适
【单选题】They all said that his high talent was the main factor of his success. But he ______ it to hard work.