You've just come home, after living abroad for a few years. Since you've been away, has this country changed for the better—or for the worse? If you've just arrived back in the UK after a fortnig
One day, a young man was cleaning out his late grandfather’s belongings when he came across a bright red envelope. Written on the front were the words, To my grandson. Recognizing his grandfather's
，高为
，若一只小虫从
点出发沿着圆柱体的侧面爬行到
点，则小虫爬行的最短路程是 （结果保留根号）
