题目

下表为某体育训练队跳高、跳远成绩的分布，共有队员40人，成绩分为1～5五个档次。例如表中所示跳高成绩为4分，跳远成绩为2分的队员为5人.将全部队员的姓名卡混合在一起，任取一张，该卡片队员的跳高成绩为x分，跳远成绩为y分.     ⑴求的值； ⑵求的概率及且的概率． 跳         远 54321 跳 高513101 410251 321043 2160 100113阅读理解。　　Once there were two brothers who were twins. They looked the same. They both had the same darkbrown hair, blue eyes and beautiful teeth. They were both 5 feet 10 inches tall and both weighed 150 pouds.　　They not only looked alike but also sounded alike on the telephone. Not even their family could tell the difference. They dressed alike, listened to the same music, and read the asme books.　　When they were twenty-tree, they both got married and a year later both had sons. The years went by and as they began to grow old, they both wore glasses and they both became. bald.　　Then one day, one of the brothers got sick and died. A few days later a man stopped the other twinon the street.　　"Excuse me for asking," he said, "but was it you or your brother who died?"1. It was not easy to tell the two men from each other because _____.A. they were brothers     B. they were handsomeC. they were the same age D. they were twins2. The twin brothers _____.A. had different coloured hair    B. were not so tall as each otherC. looked very much alike       D. wore different clothes3. "They both became bald" means _____.A. they became old            B. they had sonsC. they had little hair           D. they got sick4. The only difference between the twins was _____.A. one got sick and died first   B. one was shorter than the otherC. one got married and had a son  D. one was bald and the other wasn't5. The man stopped the other twin on the street because _____.A. he wanted to talk with him   B. he didn't know which of them diedC. he wanted to make friends with him  D. he was surprised to see him on the street.