用于枪弹的发射药现在主要是用()、()和无烟火药。
参考答案:硝化棉、硝化甘油
阅读短文,回答问题。
There are many people on a bus. A woman with a little girl gets on the bus. She gives the conductor one
yuan and says, "A ticket to the zoo, please."
The conductor looks at the little girl. Then the conductor asks her, "How old are you?"
"I'm six at home, and I'm three on the bus." The girl answers.
All the people laugh. The woman's face is red. At last, she buys another ticket for her daughter.
1. Does the woman want to buy her daughter a ticket?
2. How many tickets does the woman buy altogether (总共) ?
3. How old is the little girl?
淬火目的是什么?