题干

在平面直角坐标系中,一蚂蚁从原点O出发,按向上、向右、向下、向右的方向依次不断移动,每次移动1个单位.其行走路线如图所示.

(1)填写下列各点的坐标:A4          ​          ),A8​          ​          ​);

(2)写出点A4n的坐标(n是正整数);

(3)指出蚂蚁从点A2012到点A2013的移动方向.

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【解答】解:(1)由图可知,A4,A8都在x轴上,∵小蚂蚁每次移动1个单位,∴OA4=2,OA8=4,∴A4(2,0),A8(4,0);故答案为:2,0;4,0;(2)根据(1)OA4n=4n÷2=2n,∴点A4n的坐标(2n,0);(3)∵2012÷4=503,∴2012是4的倍数,∴从点A2012到点A

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    Living among trees, plants and flowers can fill your life with beauty. And if you are a woman, it can also help you live longer. Researchers found that women who live in homes surrounded by plants appear to have lower death rates than women who live in areas with fewer plants.

    Researchers at Harvard University's T.H. Chan School of Public Health reported the finding. They looked at the information from one of the largest and oldest investigations of the women's health: the Nurse's Health Study. It began 40 years ago. It now has information on nearly 200,000 women.

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    The study found that the death rate among women who lived in the greenest spaces was 12% lower than those from the least green areas. The researchers were surprised to find such a strong connection between high vegetation levels and low death rates.

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