The growth of population during the past few centuries is no proof that population will continue to grow straight upward toward infinity and doom. On the contrary, demographic history offers evidence that population growth has not been at all constant. According to paleo-ecologist Edward Deevey, the past million years show three momentous changes. The first, a rapid increase in population around one million B. C., followed the innovations of tool-making and tool-using. But when the new power from the use of tools had been exploited, the rate of world population growth fell and became almost stable. The next rapid jump in population started perhaps 10,000 years ago, when men began to keep herds, plow and plant the earth. Once again when initial productivity gains had been absorbed, the rate of population growth abated. These two episodes suggest that the third great change, the present rapid growth, which began in the West between 250 and 350 years ago, may also slow down when, or if technology begins to yield fewer innovations. Of course, the current knowledge revolution may continue without foreseeable end. Either way contrary to popular belief in constant geometric growth--population can be expected in the long nm to adjust to productivity. How many significant demographic changes ever occurred in the past one million years
A. One.
B. Two.
C. Three.
D. Non
I was so angry that I felt like (throw)()something at him.
Conversation 1M: Hi, Sally. Welcome back. How was the West CoastW: Terrific. I had a wonderful time. It was really nice to get away from the city for a while.M: What do you think of L. A.W: It was all right. I liked it better than I thought I would. It’s very clean and spacious, and it’s got lots of trees. The problem is transportation. The bus service is terrible, and of course, they don’t have a subway, so it’s a little difficult to get around. We had to rent a car.M: And what did you seeW: Oh, the usual things. We took a drive around Hollywood and looked at the stars’ homes, and then we went to Universal Studio and Disneyland.M: How did you like DisneylandW: It was great. We really enjoyed it. We took all the rides, some of them twice, and had a lot of fun. I felt just like a kid again.M: Was the weather goodW: Oh, yeah. It was nice and warm in L. A.. What is the problem of L. A. according to the woman()
A. The population.
B. The weather.
C. The transportation.
D. The crime.
Conversation 2M: Hey, Alice! What are you doing thereW: Hey, Royal! Could you have a look at my computer I can’t get it working.M: Sure. Let me have a look. Er, it seems that the disc is junk.W: Oh, really I just bought it yesterday.Well, then could you please go to the store with me I want to have this computer replaced.M: No problem. But you have to bring your receipt, otherwise you can’t have the computer replaced.W: Oh, dear! I can’t find my receipt. Perhaps I lost it on my way back from the store.M: That’s too bad. I’m afraid you have to find it.W: Well, I’ll give you a telephone call if I can find it.M: OK. See you then.W: Thank you. See you. What does the woman have to do to get her computer replaced()
A. To show the receipt.
B. To call the store first.
C. To pay some more money:
D. To bring the instruction manual.