RLC串联电路总的复阻抗等于三个元件的复阻抗的和。

A. 对
B. 错

X=XL+XC 称为RLC串联电路的电抗。

A. 对
B. 错

QC<0时，电容元件吸收功率；QC>0时，电容元件发出功率。

A. 对
B. 错

同电感元件一样，在一个周期内，电容元件的平均功率也为零。

A. 对
B. 错

在RLC串联正弦交流电路中，有功功率的表达式为P=UIcosψ

A. 对
B. 错

___ pictures in the park last weekend.

A. take
B. took
C. was
D. draw

Did you ___football yesterday?

A. play
B. played
C. were
D. are

He always _____me last term.

A. helped
B. helps
C. helping
D. help

They came to China in 1990.(变一般疑问句)__________ they ________ to China in 1990?

She washed the clothes last Sunday. (变否定句)She _________ ________ the clothes last Sunday.