三相四线式380V配电网属于()。
A、一次配网
B、二次配网
C、高压系统
参考答案:B
People of all ages ______beautiful costumes skipped back and forth ______the loud music.[ ]
A. dressing in; at
B. dressed in; to
C. dressing up; to
D. dressed up; at
简述菜粉蝶的为害特点与无公害防治技术?