A.由P=I2R知,R越大P就越大
B.由P=U2/R知,R越大P就越小
C.在I一定时,P与R成正比
D.在U一定时,P与R成反比
CD
— Tom, do you wear dresses? — [ ]
A. No, I never wear dresses.
B. I sometimes wear dresses.
C. I usually wear shorts.
釉柱晶体的宽是()
A.100~140nm
B.40~90nm
C.5~15nm
D.20~30nm
E.160~1000nm