阅读材料，回答问题

1500年后大量黑人被贩卖美洲，白人大批移居到北美东海岸和南美，白人与印第安人结合产生新的混血儿；与黑人结合产生黑白混血儿。病菌如天花、麻疹、白喉、水痘也随着人口流动传到美洲。欧洲人将小麦、大麦、燕麦和水果品种葡萄、橄榄带到美洲；从美洲传到东半球的粮食作物、经济作物和水果品种则更多，有玉米、马铃薯、花生、番茄、辣椒、棉花、烟草、可可豆、菠萝、木瓜等。各种吸烟方式，烟斗、鼻烟、卷烟、雪茄也源自美洲印第安人，因此而引起的健康问题，直至现今。

——摘编自姜守明《世界地理大发现》山东画报出版社，2004

根瘤菌的新陈代谢类型属于（   ）

“月落乌啼霜满天，江枫渔火对愁眠，姑苏城外寒山寺，夜半钟声到客船。”这首诗所描述的月亮是    (    )

  

“DNA是主要的遗传物质”是指（  ）    

根据短文内容，选择正确答案。
Hello, friends!
    My name is Zhou Dan. I'm a Chinese girl. I'm twelve. I'm from Zhengzhou, China. Do you know Zhengzhou? It's in the middle of China. I'm in No. 8 Middle School. There are about 900 students and 50 teachers in our school. It is a good school in Zhengzhou: I'm in Class 2 Grade 7. There are 49 students in our class: 29 girls and 20 boys. My English teacher is Miss Zhao Dan. Our names are almost the same, right? She is nice to me. We're good friends. I like English, and I like music, too. I want to find a pen-friend. Please write to me.
                                                              Yours,
                                                            Zhou Dan