题干

水葫芦是我国100多年前从国外引进的一种植物,曾一度用于净化污水,近几十年来在我国部分地方疯长.如在云嫩滇池里,水葫芦疯长,几乎遮盖了整个水面,使很多水生生物几乎绝迹.导致滇池生物多样性遭到破坏的原因是(  )

A:乱砍滥伐

B:乱捕滥杀

C:环境污染

D:外来物种入侵

上一题 下一题 0.0难度 选择题 更新时间:2017-10-18 10:03:06

答案(点此获取答案解析)

D

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    Some people seem to have extraordinary (非凡的)memories. Zheng Aiqiang, a “memory athlete” on TV show Super Brain, can remember 2,660 numbers in just one hour!

    You would think people like this have special brains. But according to a recent study by researchers from the US and the Netherlands, the brain structures(结构)of ordinary people and 23 of the world's leading memory athletes show no difference.

    That's because good memories can be trained. New research in the journal Neuron (神经元期刊) suggests that you can become a super memorizer with just six weeks of hard training.

    Researchers found that technique (技巧)called loci, invented by ancient Greeks, can greatly help improve memory. By using loci, you are using your imagination to improve the brain's memory networks. You can link(关联)something you need to remember with a place that you know very well. For example, to remember a list of numbers, imagine yourself walking through your house. Each thing is linked to a number. For example, zero could be handle(把手)on the door and five could be the painting on the wall.

    In one study, some ordinary people were given 20 minutes to remember 72 words. First they could only remember 26 of them. But when they were taught loci, they could remember 62 words.

    “Not everyone can become a memory champion. But everyone using the technique can improve a lot from the level they're at,” said Boris Konrad, one of the researchers in the study.