(CB· n=x+√3y=0,则/3CC,=02取x=√3,得n=（√3，—1，-1).设直线BA与面BCCB所成角为0，0EIBA·nl_V3√15sin θ=Icos(BA,n>| =[BAi1|n|2√5√15所以直线BA与面BCC,B所成角的正弦值为-15分1017.（1)解法一：的概率分布为1.21.181.172分111P623E()=1.2x+1.18X+1.17X1.18.4分由题设得~B(2,p),故P(=0)=Cp°(1-p)²=（1—p)²，P(=1)=Cp(1-p)=2p(1-p),P(=2)=C²p²(1-p)°=p²，则的概率分布为20P(1-p)²2p(1-p)#21.31. 250.2故的概率分布为7分P(1-p)²2p(1-p)p2所以 的数学期望为E()=1. 3×(1-p)²+1. 25×2p(1-p)+0.2×p²-0.1p+1.3.·10分1.21.181.17解法二：6的概率分布为2分111P62E()=1.2x+1.18X+1.17X1.18.4分的概率分布解法如下：设A:表示事件”第i次调整，价格下降”（i=1,2），则P(=0)=P(A)P(A)=(1-p)²,P(=1)=P(A）P(A)+P(A)PA=2p(1-p),P(=2)=P(A)P(A2)=p²,#21.31.250.2故2的概率分布为7分P(1-p)²2p(1-p)p²·数学（五）参考答案学第4页（共6页）】

23.（本题满分7分）当今,青少年使用手机、电脑等电子产品时间过多,视力水下降,这一现状已引起了全社会的关注.某校为了解八年级1 000 名学生的视力情况,从中抽查了150 名学生的视力情况,通过数据处理,得到如下的频数分布表.解答下列问题:组别视力范围分组组内均数频数A3. 95≤x

1、山西思而行 2023-2024学年高二年级1月联考物理试题2、上进联考 2024年5月江西省高二年级统一调研测试​​试题(历史)1、[上进联考]七彩联盟2023-2024学年第二学期高二年级期中联考试卷答案试题(历史)1、[上进联考]七彩联盟2023-2024学年第二学期高二年级期中联考试卷答3、［广东大联考］广东省2023年高二年级上学期10月联考x物理试卷答案金图100所名校最新惠考横机示地卷、7闭合电路内、外电阻的功率随外电路电阻变化的两条曲线如图所示，曲线A表示内电阻的功率随外电阻变化的关系图线曲线B表示外电阻的功率随外电阻变化的P/W关系图线。下列说4、百师联盟2025届高三一轮复联考(二)物理（百H）试题1、百师联盟2025届高三一轮复联考(二)生物（百H）试题1、贵阳市2025届高三年级摸底考试(2024年8月)生物试题1、贵阳市2025、贵州省黔东南州2023-2024学年度高一金太阳第一学期期末检测(24-314A)生物试题1、河北高一2023-2024学年度下学期月考(6月)答案(语文)1、安徽省2023-2024学年度高一上学期第二次月考(24031A)生物答案

秘密★启用前物理(八)试卷注意事项：1.答题前，考生务必将自已的姓名、准考证号填写在答题卡上。2.回答选择题时，选出每小题答案后，用2B铅笔把答题卡上对应题目的答案标号涂黑。如需改动、用橡皮擦干净后，再选涂其他答案标号。回答非选择题时，将答案写在答题卡上，写在本试上无效。3.考试结束后，将本试卷和答题卡一并交回。一、选择题：本题共10小题，共46分。在每小题给出的四个选项中，第1～7题只有一项符合题目要求，每小题4分；第8～10题有多项符合题目要求，每小题6分，全部选对的得6分，选对但不全的得3分，有选错的得0分。1.核污水中含有、锶、环等多种放射性元素，处理不当会对人类和动植物造成威胁。(H)的半衰期为12.5年,若将含有质量为4g的的核污水排人大海，经过100年排入海中的还剩1.11A.g区，成为中国制造的一张“亮丽名片”。在对某款新能源汽车性能测试过程中，汽车以36km/b的速度匀速行驶，检测到前方有障碍物时，汽车启动自动刹车系统立刻做匀减速直线运动开始减速，刹车距离为10m。汽车从刹车到停下的过程中A.加速度大小为10m/sB.运动时间为2sC.均速度大小为2.5m/sD.最后1s运动的位移大小为5m3.目前人们已发现绕太阳运行的彗星有1700多颗，其中哈雷彗星绕太阳一周的时间为76年。哈雷彗星的运行轨道如图所示，ac、bd分别为椭圆的长轴和短轴，运行方向为a->b-c→d。关于哈雷彗星，下列说法正确的是太阳PA.从b点运动到d点的时间大于38年B.从b点运动到d点的时间等于38年C,从a点运动到c点的过程中，机械能逐渐减小D.从a点运动到c点的过程中，机械能逐渐增大

1、金太阳云南省2024-2025学年高二年级开学考(25-12B)物理B1答案1、河北省金太阳2024-2025学年高二年级七月份考试(25-03B)生物试题1、河北省2022-2023学年六校联盟高二年级下学期期末联考(232824D)生物

裁汰提高论材料在概况立时段晚清时期民国初期食负担沉重。新中国成立初期年的水。三线建设时期1982年粮食产量突破400亿斤，农村生产力解放推动粮食市场化，成都改革开放原形成全国性粮油交易中心；1990年代农民工向沿海流动，服务于沿海城时期市化建设。据贾大泉、陈世松《四川通史》19.阅读材料，完成下列要求。（15分）材料

五四制八年级（下)Unit 3 基础能力训练听力原文及参考答案听力原文I．听句子，根据所听内容选择合适的应答语。句子读两遍。1. Would you like to go to Beijing on vacation?2. What would you like to do during this summer vacation?3. I'm going to travel around the world next year.4. How do you like Paris, the capital of France?5. Do you want to sail across the Pacific?Ⅱ．听对话和问题，根据所听内容选择正确答案。对话和问题读两遍。6. M: Would you like to go to India or Japan on vacation, Jane?W: Neither, Peter. I wish to go to Canada one day.M: Canada is a great country to take a holiday. I'd like to visit it, too.Q: Which country would Peter like to go to?7. M: I like exciting vacations, so I often go to different cities. How about you, Lisa?W: Bill, cities are really interest-ing. But I'm different. I like to go somewhere peaceful.M: Oh, I see. Then you must like visiting a small town or a quiet village.Q: What kind of vacations does Lisa like?8. M: Anna, tomorrow is Sunday. How about going to the park?W: Well, the park is big and nice, but there are always too many people on weekends.M: OK. So you'd like to visit somewhere peaceful, right?Q: Why doesn't Anna want to go to the park?9. W: What would you like to be when you grow up, Dave?M: I wish to be an engineer because I'm interested in science. What about you, Sandy?W: I used to dream of being a teacher. But now I'm dreaming of becoming a doctor. Then I canhelp sick people.Q: What does Sandy want to be when she grows up?10. W: Would you like to visit Xi'an this vacation with me, Tony?M: Why not, Anna? I hear it's an ancient and beautiful city.W: That's true. How are we going to get there, by bus or by train?M: I don't care as long as we can arrive there safely.Q: Which is TRUE about the conversation?Ⅲ.听对话，根据所听内容选择正确答案。对话读两遍。听第一段对话，回答第11-12小题。M: Judy, there will be a new movie tonight. Would you like to go to the cinema with me?W: I'd love to, Henry, but I have to finish my homework.M: What a pity! How about tomorrow evening?W: Let me see. Oh, that's OK. But I'd like to take my sister Ann with me. May I?M: No problem. See you then.W: See you.听第二段对话，回答第13-15小题。M: Vivian, the summer vacation is coming. Where would you like to visit?

BLakshmi spends several hours each day digging out large yams ( ili 药 ） that grow below the soil.Some weigh 5 kg and are 4.5 ft long, almost as tall as she is. “It's painstaking work,” says 58-year-oldLakshmi.答案解析网Lakshmi, who lives in the southern Indian state of Kerala, isn't working alone. She's part of anall-women group called Noorang. The members all belong to one of Kerala's oldest local tribes ( 部落 ), aon their landfor centuries.答案解析网号But yams are no longer a main diet among tribal communities in Kerala due to their evolving living生答案解析网patterns. Younger people who have ready access to a wide variety of other foods, especially rice and题·····wheat, no longer consider the yams that once nourished their ancestors anything special.Extreme weather destroyed yam harvests in the past. Frequent flooding and deadly landslides caused答many yams to die. Recently, there was a sharp decline in lands dedicated to yam production in Kerala,位号要with many of these being changed into rubber cultivation（培育）instead.答案解析网"Primarily, the women growing these yams are doing so to nourish their own families, and to ensure下that these ancient rare varieties don't fade away,” Lakshmi says. “"We believe in the medicinal value·····.of these local yams,” says Shantha, another member of Noorang. “Most mothers here will swear by its内·····.ability to cure digestive and stomach problems.”答案解析网名姓Since their formation in 2022, the 10 members of Noorang have planted and brought back to线：：the community 180 varieties of wild yams, including three varieties of elephant yams, eight types of：封·····varieties of rare seeds as we can find and to cultivate more yams,”' says Sarasu, a member of Noorang弥级24.What is the purpose of Noorang？答案解析网班A. To boost yam sales in commercial markets.答案解析网B.To innovate yam farming techniques.答案解析网C. To safeguard native agricultural heritage.答案解析网D. To challenge modern agricultural trends.答案解析网校答案解析网25. What primarily accounts for the decline of yams in local diets? 答案解析网A. Insufficient awareness of their medicinal properties.答案解析网B.Changing dietaryhabits influenced by the new lifestyle.答案解析网C. Government restrictions on traditional crop cultivation.答案解析网D. Limited adaptability of yams to climate change.

1、金太阳卓越联盟2024-2025学年高二第一学期第一次月考(25-60B)文数试题1、金太阳2025届湖南省高三年级入学考试(HUN)物理答案1、河北省2023-2024学年第一学期高一金太阳期末调研考试(24-176A)数学答案

全国100所名校高考冲刺卷d区d区电c区c区序流温度/℃温度/℃溶液/10mL溶液/10mL号25251 mol·L-的CuSO溶液1X10-mol·L-的CuSO溶液I225251 mol · L-的 CuSO 溶液X的溶液225251×10-mol · L-的 CuSO 溶液I33Y的溶液902541 mol · L-的 CuSO4 溶液1 mol ·L-的CuSO溶液I90901 mol· L-的 CuSO4 溶液5①实验过程中测得II3,得出的实验结论为温度不变时，浓度对电池电弥势存在影响。则d区溶液 X 为,Y为②通过对比实验4、5、（填“1"“2"或“3"），得出的实验结论为浓度不变时，温度对电池电势存在影响，测得的电流的大小关系应为(3)结合论分析上述实验结果，已知池电势可表示为E=E°2.303 RT正极31[E（标准nFnFC正极（Cu²C负极(Cu²+)电势)与浓度、温度无关,R、F 为常数,n 为转移的电子数,T 为温度(单位为K)]。封利用上述知识解释温度不变时，改变两极区域中铜离子浓度对电池电势存在影响的原因：若想增大实验过程中电池的电势，结合实K验结果和计算公式，可知除了增大浓度差外，还可以18. (14 分)高冰镍(主要含 Ni2 Ss、Cu2S、Fe; O4、CoS 等)氨法浸出及利用氨浸液制备电池级硫酸镍的工艺流程如图7所示。H·HNLix54-100萃取剂NH3(NH高冰镍—→浸出浸出液多级萃取水相-蒸氨结晶热解→NiSO线0有机相NiSO4 · 6H,O系列操作图 7 已知: I . K,(NH; · H2O)=4. 7X10-5 ,K s,[Ni(OH)2]=10-16 ;Ⅱ.硫酸铵的熔点为 280°℃,硫酸镍的熔点为 840°℃。形式存(1)浸出液中金属元素主要以[Ni(NH)。J²+、[Co(NHs)。]²+和为(2)有机萃取剂 Lix54-100 在“多级萃取"中与金属形成配离子,水相中元素含量变化如表所示,该萃取剂对 Ni、Co、Cu的配位能力按从大到小的排序为[25 · (新高考)CCJ· 化学·G DONG)化学卷（一）第5页（共8页）