A. You're welcome.
B. What shape would you like?
C. I'd like some cherries, too.
D. What kind of pudding would you like?
E. Yes. I want to buy a pudding.
A: Can I help you?
B:____
A:____
B: I'd like a chocolate pudding.
B: I'd like a heart-shaped pudding.
A: Anything else?
B:____How much are they?
A: 70 yuan.
B: Here is the money.
A: Thank you.
空气的成分按体积百分数计算,大约是氮气占78%,氧气占 ____ ,稀有气体占____ ,二氧化碳占____ ,其它气体和杂质占____ .
一台电风扇和一个电熨斗,如果使用时消耗的电能相同,电能转化为内能( )