一名射击运动员连续射靶8次，命中的环数如下：8、9、10、9、8、7、10、8，这名运动员射击环数的众数和中位数分别是（）。
A.3与8
B.8与8.5
C.8.5与9
D.8与9
参考答案：B
解析：众数是指在一个数列中，出现频率最多的一个数；中位数是指对一组数进行排序（从大到小或从小到大）后，正中间的一个数（数字个数为奇数）或者中间两个数的平均数（数字个数为偶数）。从题中观察可得8出现了3次，出现次数最多，对该组数字进行排序（从小到大）为：7、8、8、8、9、9、10、10，中间两个数是8和9，所以其中位数是（8+9）÷2，即8.5，答案为B。
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| Recently, I stopped by a convenience store to get a newspaper and a bottle of drink. The young woman at the checkout counter said, "That'll be five dollars __1__ please." She then __2__ down at the paper I was __3__ and said, "I'm sick and __4__ all this negative (消极的) stuff on the front __5__. I want to read some __6__ news for a change." She then said, "In fact, I think someone should just __7__ a Good News newspaper-a paper with wonderful, inspirational __8__ about people overcoming difficulty and doing good things for __9__. I'd buy one every day!" She then 10 me for coming in and said, "Maybe we'll get some good news, " and she laughed. She made my day. The following day after my business appointments, I 11 the same store again to 12 bottled water and a piece of newspaper, but a 13 young lady was behind the counter. As I checked out I said, "Good afternoon" and handed her my 14 . She said nothing-not a word, not a smile or not a gesture. She just handed me my change and 15 a negative tone ordered…"Next!" It hit me right between the eyes: Two people, the same age; 16 made me feel great, and the other, well, made me feel that I had inconvenienced her by 17 . Every morning, you should ask 18 this important question: "Who do I want to be today? 'The Grouch (不高兴的人)' or 'The Good News Girl'"? Your answer will do great good to 19 the joy and happiness that you will experience in your 20 . | ||||
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