已知两个正弦量分别为i1=1sin（314t+60），i2=20sin（314t+60）则i1与i2的相位差为
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交流电压u=311sin（314t-30)V 写出最大值 有效值 频率 初相
What is the classic American Dream?
A. Owning every possession.
B. Achieving success in career.
C. Sharing with access.
D. Having a happy family.
What is the millenial American Dream?
A. Owning every possession.
B. Achieving success in career.
C. Sharing with access.
D. Having a happy family.
Why is sharing economy appealing?
A. Sharing economy makes it possible for people to have access to things they may not afford.
B. It is not a smart financial decision for people to own everything.
C. More and more non-traditional renting options come into being which provide a continuing source.
D. Sharing economy is a long-lasting trend created by millennials.
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