已知$\left|\overrightarrow{a}\right|=1,\left|\overrightarrow{b}\right|=3,<\overrightarrow{a},\overrightarrow{b}>={60}^{°},(\overrightarrow{a}-\overrightarrow{c})(\overrightarrow{b}-\overrightarrow{c})=0,$则$\left|\overrightarrow{c}\right|$的最小值是(     )

阅读下面材料, 从A、B、C、D四个选项中选出最佳选项。

    Jumping rope(绳子)is a sport any student can learn to do．You can jump alone or with a friend．You can also help turn a long rope for many others to jump over．If you jump alone, you will need a short rope which should be just long enough for you．

    A rope should be turned slowly．It must also be turned high enough to let you jump safely．Turning the rope safely needs careful timing．In rope jumping, timing means turning the rope slowly enough so that you can jump over it at the right time without its hitting your feet．

  You will notice that when you jump rope, you breathe(呼吸)faster and your face has a healthy colour．But, if you jump too many times at first, you will get too tired．You must learn when to stop for rest(休息)before you jump again．As you practice, you can increase the number(次数)of times you jump without resting．

重新排列下面句子的顺序，组成语意连贯的一段话，正确的顺序应该是（   ）

①尤其是不要忽视老人的每一个细小的请求。
②生命无常。
③因为有着这样一个遗憾，所以我时常提醒自己，善待身边的每一个人。
④或许是他走这个世界寻求的最后一丝温暖。
⑤那或许会成为他生命中的最后一个留言。
⑥尤其是走人暮年的生命更是薄如蝉翼，让人无法预料。

读《简·爱》，说按照时间顺序写了主人公在四个主要地方的生活，这四个主要地方是？