题目

为了估计不透明的袋子里装有多少白球，先从袋中摸出10个球都做上标记，然后放回袋中去，充分摇匀后再摸出10个球，发现其中有一个球有记，那么你估计袋中大约有______个白球.     A．10B．20C．100D．121 答案：C解析:略Is the world too crowded? Well, that’s a hard question to answer. It’s all a matter of perspective(视角).In Montana, you might drive for a mile in any direction and not see another human being. In Macao, 60,000 people live in every square mile!What is true is that the world’s population doesn’t stay the same. It has been increasing at a very fast rate(比例).That’s in part because in each generation(代) these are more people who then have children than in the last generation.Five hundred years ago, the population of the world was about 460 million. In 1900,the world’s population was under 2 billion(十亿).Right now it is doubling every 40 years. That means, if this rate of growth continues, when you are a parent, there will be twice as many people on earth as there are now. Wow! Now that’s a whole lot of people! Soon the world’s population will probably reach 7 billion. Some people worry about that! But there is a lot of disagreement about just how many people on earth equals(相当于) too many people. But everyone agrees that the more people there are, the more resources(资源) the world needs to feed, house and take care of all of them, and the more need there is to think carefully about how we live and use the earth’s resources.【小题1】From the first paragraph we can know that ­________.A．Montana is too crowdedB．Macao is too crowdedC．the world is too crowdedD．the world is not too crowded【小题2】The population is increasing fast partly because ________.A．people live longer than beforeB．there are less wars than beforeC．medicine is developing faster than beforeD．more couples now would like to have children than before【小题3】What was the world’s population 100 years ago?A．450 million.B．about 2 billion.C．40 billion.D．7 billion.【小题4】The writer thinks that with the population increasing, we should ________.A．find more resourcesB．use more resourcesC．think about our ways of livingD．move to other places【小题5】From the passage we can learn that the writer ________.A．thinks the world already has too many peopleB．thinks the world can feed no more than 7 billion peopleC．is not sure when the world’s population will reach 7 billionD．is not sure what the largest population that the world can feed is