题干

    A famous teacher was speaking to the students at our school. He began his lesson by holding up a ¥100 bill. Then he said to the three hundred students,“Who would like this ¥100 bill?” The students began to put up their hands at once.
    Then he said,“I am going to give this ¥100 to one of you, but first, let me do this.” He then made the bill into a ball. Then he said, “Who wants it now?” The hands went back into the air.
  “Well,” he said,“What if I do this?” and he dropped it on the floor and stepped on it. He picked up the dirty, crumpled bill and said, “Who still wants it?” Hands went back into the air.
  “My friends,” he said, “you have learned a valua-ble lesson today. No matter  what I did to the money, you still wanted it because it did not go down in value (价值). It was still worth ¥ l00!”
    Many times in our lives, we are dropped, crum-pled, and stepped on by the chances we take and the things that happen to us. We feel as if we are worth nothing. But remember, no matter what has happened to you, you will never lose your value: you are always valuable to those people who love you. Your value doesn't come from what you do or whom you know, but WHO YOU ARE.
You are special and valuable. Don't ever forget it!

上一题 下一题 0.0难度 选择题 更新时间:2019-01-19 11:23:41

答案(点此获取答案解析)

同类题4

以下是对相关生态系统的研究.根据相关信息,回答下列问题:

Ⅰ.湿地是地球上重要的生态系统,具有稳定环境、物种保护及资源供应等功能.

(1)某湿地由浅水区向陆地方向依次生长着芦苇、碱蓬、柽柳等,这体现了群落的____ 结构.调查湿地中芦苇的种群密度常用____ 法.

(2)该湿地态系统总面积为250km2,假设该生态系统的食物链为甲种植物→乙种动物→丙种动物,乙种动物种群的K值为1000头,调查发现该生态系统中乙种动物种群数量为550头,则该生态系统中乙种动物的种群密度为____ ;当乙种动物的种群密度为____ 时,其种群增长速度最快.

Ⅱ.果园可作为一个生态系统进行管理.

(3)利用生物防治方法可控制果园害虫种群密度,如用信息素壬烯醇诱捕害虫丽金龟雄虫,可破坏其种群____ 

(4)科研人员对板栗园内的栗瘿蜂和长尾小蜂的数量进行了连续5年的检测,结果如图1.据此判断这两个物种的种间关系是____ 

(5)如果不对果园土壤进行管理,果树林下将会出现从一年生草木植物为优势,到多年生草本植物为优势,再到草本与灌木混生等阶段的演替.在草本与灌木混生阶段,果园内很少有一年生草本植物生长,其原因是____ .(从种间关系的角度作答).该演替属于.

Ⅲ.某红树林生态系统各组成成分关系如图2所示.

(6)图中A表示____ ,生物成分F表示____ 

(7)请写出图中涉及的食物链:____  .