搜题请搜索小程序“爱下问搜题”
问题 单项选择题

发生燃烧和火灾必须同时具备的条件是( )。

A．氧化剂、明火、点火源
B．氧化剂、可燃物、点火源
C．氧化剂、可燃物、木材
D．阻燃剂、可燃物、点火源

答案

参考答案：B

解析：本题考查燃烧的三要素。同时具备氧化剂、可燃物、点火源，即为火的三要素。

阅读理解

阅读理解。选择正确的答案。

      Hello, my name is Betty. On Saturday, I have dinner with my parents in a restaurant. Each of us likes

different food. I have chicken and potatoes. My mother likes fish and tofu. My father has mutton and cabbage.

1. What's the girl's name? 

A. Mary.

B. Amy.

C. Betty.

2. Where do they have dinner on Saturday? 

A. At school.

B. In a restaurant.

C. At home.

3. What does the girl have? 

A. Chicken and potatoes.

B. Fish and tofu.

C. Chicken and tofu.

4. What does her mother like? 

A. Mutton and cabbage.

B. Fish and tofu.

C. Chicken and potatoes.

5. Who has mutton and cabbage? 

A. Betty's mother.

B. Betty's father.

C. Betty.
查看答案
选择题

下列说法中不正确的是（　　）

A．金属与电解质溶液的导电微粒不相同

B．在水溶液中或熔融状态下能导电的物质属于电解质

C．摩尔质量是物质的基本属性，不因为物质质量的多少而改变

D．氯化钡溶液与稀硫酸反应和氯化钡与硫酸钠溶液反应的离子方程式相同
查看答案