将含有15克A，10克B，9克C的粉末状混合物充分加热，发生化学反应后，A剩余3克，B增至25克，C已消耗完，并有气体D放出，D的质量为（ ）
A．34克
B．16克
C．6克
D．5克
将含有15克A，10克B，9克C的粉末状混合物充分加热，发生化学反应后，A剩余3克，B增至25克，C已消耗完，并有气体D放出，说明A、C是反应物，B、D是生成物，且参加反应的A的质量为15g-3g=12g；参加反应C的质量为9g-0g=9g；生成的B的质量为25g-10g=15g；则由质量守恒定律，生成气体D的质量为12g+9g-15g=6g．
故选C．
| 阅读下列图表，从每题所给的A、B、C三个选项中，选出最佳选项回答问题或完成句子。 | |||||||||||||||||||||
1. You can buy _____ kinds of fruits in Miss White's Fruit Store.  | |||||||||||||||||||||
[ ] | |||||||||||||||||||||
| A. four B. five C. six | |||||||||||||||||||||
2. How much are the pants?  | |||||||||||||||||||||
[ ] | |||||||||||||||||||||
| A. Twelve dollars. B. Thirteen dollars. C. Eighteen dollars. | |||||||||||||||||||||
3. Lily wants to speak English well. She can buy _____. | |||||||||||||||||||||
[ ] | |||||||||||||||||||||
| A. Skills for English Listening and Speaking B. 100 English Stories C. Learning English in Your Car | |||||||||||||||||||||
4. In the afternoon, _____ is Li Lei's first class.
| |||||||||||||||||||||
[ ] | |||||||||||||||||||||
| A. science B. music C. P.E. | |||||||||||||||||||||
5. The card doesn't show ______.  | |||||||||||||||||||||
[ ] | |||||||||||||||||||||
| A. the name B. the telephone number C. the address |
干扰