固体酒精.液体酒精和酒精蒸汽都能燃烧,这些现象说明( )
A:分子始终做无规则的运动
B:分子之间存在间隙
C:分子之间存在引力和斥力
D:分子是保持物质化学性质的最小粒子
每个哈尼族人必备的生活本领是( )
⑴Happy New Year.____ A. It's red.
⑵What color is the car?____ B. Thank you.
⑶What is that?____ C. Happy New Year.
⑷This doll is for you.____ D. It's a ball.
⑸Would you like a pie?____ E. No, thank you.
矩形线圈在匀强磁场中匀速转动,所产生的交变电流的波形如图所示,下列说法中正确的是( )