【简答题】求下列齐次线性方程组的通解: (1) (2) (3) (4)
【简答题】简述果蔬原料分级、清洗的目的和主要方法。
【单选题】在空载,短路,负载实验中,U0,I0,P0,UK,IK,PK,P1分别代表什么?各等于多少?
A.
U0代表空载实验时,三相空载电压的平均值,I0代表空载实验时,三相空载电流的平均值,P0是三相空载实验时,两块功率表读值的代数和,UK代表短路实验时,三相短路电压的平均值,IK代表短路实验时,三相短路电流的平均值,PK是三相短路实验时,两块功率表读值的代数和,P1为负载实验时,两块功率表读值的代数和。
B.
U0代表空载实验时,三相空载电压的平均值,I0代表空载实验时,三相空载电流的平均值,P0是三相空载实验时,两块功率表读值的绝对值之和,UK代表短路实验时,三相短路电压的平均值,IK代表短路实验时,三相短路电流的平均值,PK是三相短路实验时,两块功率表读值的绝对值之和,P1为负载实验时,两块功率表读值的绝对值之和。
【单选题】在《岳阳楼记》中写下“先天下之忧而忧,后天下之乐而乐”历史名句的是
【单选题】Section A 听力原文:W: It's awfully dark for 4 o'clock. Do you think it's going to rain? M: You'd better do something about that watch of yours. It must have stopped hours ago. Nine says 7. Q: What conclus...
A.
Neither of their watches keeps good time.
B.
The woman's watch stopped 3 hours ago.
C.
The man's watch goes too fast.
D.
It's too dark for the woman to read her watch.
【单选题】— It's too dark and I can't see it clearly. Would you mind _____ the light? — No problem. [ ]
【简答题】求下列非齐次线性方程组的通解: (1) (2) (3) (4)