A:上腔静脉
B:下腔静脉
C:肺动脉
D:肺静脉
如图所示试管中装有水,用带玻璃管的胶塞塞住,在玻璃管口处放一个纸做的小叶轮,加热试管使水沸腾后,小叶轮转动,下列说法正确的是( )
学习化学可以了解日常生活中某些变化的本质,下列变化中属于化学变化的是( )
下列各句中标点符号使用有错误的一项是( )
A. Let's go.
B. Are these your shoes?
C. Let's play football.
D. They are on your feet.
E. What are they?
A:It's warm today.____
B:Great!____
A:Where are my shoes?
B:____
A:No.they aren't.
A:Look!____
B:Oh.I'm sorry.