在国际单位制(SI)中电流(A)是基本单位,电压(V)是导出单位。
参考答案:对
---Do you often go swimming in summer?
---No, _________.Swimming is a good kind of sports, but I can’t swim.
A.sometimes
B.often
C.always
D.never
均质连续的物体,其重心决定于该物体的()。
A.形状
B.质量
C.体积
D.面积