1.简答题- (共1题)
2.单选题- (共4题)

A. 硒的原子结构示意图中x=6
B. 硒原子的中子数是34
C. 硒属于金属元素
D. 硒的相对原子质量是78.96g
A. 空气是由多种单质和化合物组成的混合物
B. 空气中含量较多且化学性质活泼的是氮气
C. 呼吸、燃烧、炼钢、化工生产等都要用到氧气
D. 空气是一种宝贵的自然资源,要保护空气,防止污染空气
3.选择题- (共1题)
My name is Jim and I live in Canada. My mother is from Korea and my father is from France, so we speak three languages(语言) at home. I think languages are very interesting and I want to learn Portuguese and Chinese. But my favorite subject isn't language. It's math. I really like history, too.
I like sports, especially(尤其) soccer and basketball, because they're relaxing. But I don't have much time to play. I go to the music club after school on Mondays. I have guitar lessons on Wednesdays, and I go to the library(图书馆) on Fridays. Saturdays and Sundays are great, because I can play sports, play computer games and watch TV.
4.填空题- (共4题)

A.实验说明水是由氢分子和氧原子构成的 |
B.电解水的文字表达式:水![]() |
C.乙试管内产生的气体能使带火星的木条复燃 |
D.甲、乙两试管产生的气体质量之比为1∶2 |
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【1】题量占比
简答题:(1道)
单选题:(4道)
选择题:(1道)
填空题:(4道)
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【2】:难度分析
1星难题:0
2星难题:0
3星难题:0
4星难题:1
5星难题:0
6星难题:5
7星难题:0
8星难题:1
9星难题:2