同种生物同一性状的不同表现形式称为相对性状，下列属于相对性状的是（　　）

材料一：2016年10月19日国家统计局发布了前三季国民经济的主要数据，按可比价格计算，前三季度国内生产总值同比增长6．9%，国民经济运行保持了总体平衡，稳中有进、稳中提质的发展态势。

材料二：目前，我国总体上已进入以工促农，以城带乡的发展阶段，国家的经济实力、综合国力显著增强，可以拿出更多的财力支持农业和农村发展，各级政府切实把基础设施建设和社会事业发展的重点转向农村，国家财政新增教育、卫生、文化等事业经费和固定资产投资增量主要用于农村，逐步加大政府土地出让收入用于农村的比重，通过强化各项支农惠农财税政策，包括严格执行增加投入政策，加大支农补贴力度、支持在全国范围建立农村最低生活保障制度、促进现当代农业建设等，加快社会主义新农村建设。

根据短文内容，完成下列各题。

      Grace was fourteen years old and was in Grade Eight. She had a part-time job, so she had to get up at five o'clock. She was a newspaper girl.

      Each morning, Grace left the house at 5:15. She always rode a bike to the corner to carry the newspapers.

      In winter it was still dark when she got up, but during the rest of the day it was bright. Grace had to send newspapers to people's houses in all kinds of weather. She tried to put each paper in the box where it would be kept safe from wind, rain or snow. Her customers thought she did a good job. Sometimes they gave her tips(小费).

      Grace made about $70 each month and she was saving some of the money to go to college. She spent the rest on tapes and clothes. Once a month she got the money from her customers together. Since many of them worked during the day, Grace had to get the money at night. Sometimes when Grace was ill, her elder brother had to send the newspapers and Grace's father had to help her.

      Grace had 70 customers now, but she hoped to get more later. Some day, if she got more customers, perhaps Grace could win a prize for being a very good newspaper girl. She wanted to win a visit to Europe, but she would be happy if she won a new bike.