根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。

    Today is Sunday. The clothes at Mr. Wang's Clothes Store 1 on sale. So I want to buy some clothes 2 my grandparents, parents and myself. Let 3 have a look. This yellow sweater is at a very good 4 — only 16 dollars. And it is OK for my 5. For my grandmother I want to buy those black 6. They are comfortable (舒适的). 7 about this white T-shirt? Oh, my father can wear (穿) it to 8 basketball. And there are many socks in all kinds of colors. I know my mother 9 green very much. So I will buy these green ones. For me I 10 a pair of blue shorts.

网约车技术引进我国之后，已发展成为一个庞大的产业，据统计，现在每天有1400多万人通过手机约车，享受着出行的廉价与便捷。对“网约车”下列说法正确的是（　　）

①科技深刻影响着我们的生活                                ②网约车既能让人民利用自己的资源满足社会的需要，也能给自己创造经济价值

③更多地引进科技就能使我国成为科技强国        ④创新是时代的召唤

汽车与水平路面的动摩擦因数μ=0.2，当汽车在半径为R=200m的弯道上转弯不打滑时，行驶的最大速率为多少？（滑动摩擦力等于最大静摩擦力）