A:食物链是指一定区域内各种生物之间由于食物关系所形成的联系
B:食物网是指不同种类的多条食物链平行连接起来形成的简单结构
C:食物链和食物网是生态系统的营养结构,它与能量流动无关
D:食物链和食物网破坏不会影响生态系统自我调节能力的大小
只有勤于思考、善于总结,才能不断提高我们对历史人物、历史事件、历史现象的认识水平。学完七年级下册第一、二单元后,李老师在帮助学生复习时对部分问题进行了归纳设计,请你一起来完成设计内容。 【历史线索篇】 【和谐盛世篇】 【民族关系篇】 中国自古以来就是一个统一的多民族的国家,各朝统治者处理民族关系的政策也为后人留下深刻的启示和教训。 【学习收获篇】 【学以致用篇】
根据句子意思,写出下列句子括号内所给单词的正确形式。The children often get ____ (noise) in the classroom after class .Sometimes he spends his weekend____ (fish).Several____ (foreign)came to visit our school last week.I think the red skirt looks as ____ (good)as the green one .John just got his____ (driver) license.Look!Mrs Li is there. Let's go and say hello to____ (she)?My mother often____ (enjoy) the TV plays in the evening.Talking loudly in a library is very____ (polite).B.根据句子意思及所给的首字母或汉语提示,写出该句子中所缺的单词。Li Na is a famous tennis p____ .We can’t l____ to music when the teacher is talking in class.The children had a____ been asleep when I got home .Mr Li is s____ with his students and makes them work hard.Zhou Gu was____ (采访)by the local newspaper.There are ____ (五十二)weeks in a year.The doctor gave him some medicine for his serious____ (疾病)。