A：Na与水反应，Na块越大现象越明显
B：在实验室中钠保存于石蜡油或煤油中
C：Na在空气中燃烧，产物是Na2O
D：Na是银白色金属，硬度大，熔点高
阅读短文，下列问题
B
Amy
I like singing. I can play the guitar and the piano. I want to join the music club.
Bill
Do you want to know my favorite sport? I like playing basketball very much.
I can playing it well.
Jackie
I like playing the piano very much. I often play the piano after school.
Frank
My favorite sport is playing soccer, and I’m good at it.
He believes that these ____ a common____, an animal that lived in Asia some 300,000 years ago.
在自然界中，每一种生物几乎都受到周围其他生物的影响。以下哪项不符合“甲减少，乙随之减少”（ ）
“五一”劳动节是全世界劳动人民的节日,这一节日的设立是对劳动者的尊重和爱戴,这是因为( )
①劳动创造物质财富和精神财富 ②劳动是人类文明进步发展的源泉 ③劳动光荣 ④劳动者是生产过程的主体,在生产力发展中起主导作用
