英语 暑假综合练习12-【快乐假期•暑假作业】七年级合订

快乐假朗 15.2解析：(y,3)★(1-y,y-1)=户y气 3 y -5,.3+y=-5(1-y),解得y=2. 16.(1)2(2)-3 17.解：(1)原式=1+3-4=0.(2)原式=ab(a-b)(a +b) 3x+4y=5① 18.解：(1)原方程组整理得 3×①+ 10x-3y=-2②， 4X②得49x=-1,解得x=,代人①，得y=, x= 7 原方程组的解为 (2)3x-10_2x-12 8 x-3x2-9 y=7 3,方程去分母得(3x一10)(x十3)一(2x一12)= 3(x2-9),整理得-3x-18=一27，解得x=3,经检 验，x=3为原方程的增根，∴原分式方程无解. 1”解：服式-气·+》2+ r+2 (x+2)(x-2) =x+2+x-2=2.“ x一2≠0， x2-4≠0， .x≠2，x≠一2，x≠0，.取x=1,得原 x+2≠0， x≠0， 式=2；取x=-1,得原式=-2. 20.解：(1)15÷30%=50（人），50-15-8-17=10 (幅)，图略.(2)10÷50×100%=20%，20%× 360°=72.(3)500×品=80（幅），全年级剪纸 作品约有80幅. 21.解：(1)平行.理由：，∠2=∠BME,∠1=∠2， ∠1=∠BME,AE∥FD.(2)AE∥FD, ∠A=∠BFD.又∠A=∠D,∴∠BFD=∠D, AB∥CD,.∠C=∠B=30. 22.解：(1)设租了x辆大巴车，由题意得45x十30=50 (x-1)+50-10,解得x=8,45×8+30=390(人)， .七年级共有390名学生，共租了8辆大巴车. (2)设大巴车速度为a千米/时，张老师追上大巴车 的地点到根博园的路程为6千米.由题意得120 1201+1 .6a-2+4,解得a=60,1.6X60=96(千米/时)， ÷当张老师追上大巴车时，129。+日-120解 96 2 ·88· 得b=40,∴张老师追上大巴车的地点到根博园的 路程为40千米. 23.解：(1)x-2y-28-y(2)由题意得，HE= AE-AH=5-(x-2)=7-x,EB=QI=x-5,NM =NL-ML=NL-GK=y-5,S=JH.HE=2(7 -x)=14-2x,S2=GK·GM=3(8-y)=24-3y, S=FQ·QI+NM·NC=(5-2)(x-5)+(y-5) (x-3)=xy-2x-3y.S+S2=S-4,.(14- 2x)+(24-3y)=(xy-2x-3y)-4,整理得xy= 42,.S长方形AD=AB·AD=xy=42.(3)空白部 分独有的周长为DN+DG+KA十AH+EB+IB= 3+(y-5)+(y-3)+(x-2)+(x-5)+2=2(x+ y)-10,阴影部分独有的周长为NC+CI+HE+ GK=(x-3)+(y-2)+(7-x)+(8-y)=10.. 空白部分的周长比阴影部分的周长大6，，.2(x十y) -10=10+6,整理得x+y=13.xy=42,.∴.(y一 x)2=(x+y)2-4xy=132-4×42=1, 「x+y=13, x=7, y-1,解得 y=6. 暑假综合练习八 1.him 2.us 3.yours 4.her 5.his 6.mine 7.himself 8.Mine 9.hers 10.Its 11.Their 12.my 13.ours 14.Whose 15.me 16.B 17.B 18.B19.B20.D21.C22.A23.B24.C 25.C26.B27.C28.A29.D30.C 暑假综合练习九 1.women 2.children 3.men 4.wives 5.watches 6.cities 7.pencil boxes 8.knives 9.glasses 10.stories11.D12.C13.B14.A15.A16.B 17.A18.C19.D20.D21.C22.A23.D 24.C25.C 暑假综合练习十 1.A2.B3.B4.C5.A6.B7.B8.C9.C 10.C11.B12.D13.C14.A15.D 暑假综合练习十一 1.D2.C3.A4.B5.C6.D7.B8.C9.D 10.A11.C12.B13.B14.A15.D16.D 17.D 暑假综合练习十二 1.a;The 2.an;the 3.an;a 4.the 5./;/6./;the 7.the;a 8.the 9.the 10.the;the 11.C 12.B 13.A14.B15.C16.E17.B18.A19.F20.D 暑假综合练习十三 1.B2.D3.A4.B5.A6.A7.D8.C9.C 10.B11.A12.C13.B14.B15.B16.A 17.D18.C19.A20.B21.T22.F23.F 24.T25.T 暑假综合练习十四 1.D解析：氢氧化钠溶于水放热，可使石蜡受热熔化。 2.B解析：⑧是卵细胞，受精后变成受精卵，将来发育 成种子的主要部分胚；桃花异花传粉过程主要借助昆 虫来完成；图中有两性细胞的结合，属于有性生殖。 3.C4.D 5.A解析：根据题意可知t=s/v=1.3×1012m/(3× 103m/s)≈4.33×103s≈1.2h。 6.C解析：②是水蒸气放热液化现象，④是水蒸气放 热凝华现象。 7.B解析：空气污染物主要是污染性气体和可吸入颗 粒物。 8.B解析：燕子产的卵是一个受精卵；燕子卵中的胚 盘含遗传物质，是发育成雏鸟的结构；小燕子和母体 的形态结构差别不大，不属于变态发育。 9.D解析：D项操作木条燃烧消耗较多氧气，不利于 铁丝的燃烧。 10.D解析：根据题图可知Q接电源负极；乙中产生的 气体是氧气，不可以燃烧，但可以助燃；实验产生A、 B两种气体的体积之比为2：1。 11.C解析：蜻蜓是不完全变态发育，发育过程可表示 为D+A+C;C为成虫期；若表示蚕的发育过程，应 设法延长A幼虫期。 12.B解析：群落是一定范围内所有生物的集合。 13.C14.A 15.B解析：图甲中a固体有剩余，故两溶液的溶质质 量不相等；N是b物质的溶解度曲线；根据图丙可 知，30℃时，两溶液的溶质质量分数相等。 16.（1)氧气(2)二氧化碳(3)水蒸气 17.(1)晶体固液共存(2)96小于(3)b 18.②④ 19.(1)剧烈燃烧、火星四射、生成黑色固体铁十氧气 点燃四氧化三铁(2)防止高温熔融物掉落使集气 暑假作业·七年级 瓶炸裂 20.出芽生殖② 21.②③④⑦①⑥ 22.(1)草→鼠→猫头鹰(2)分解者(3)自动调节能 力(4)递减 23.(1)紫(2)能 24.(1)30无影响(2)B 25.(1)小玻璃罩中蜡烛燃烧产生热的二氧化碳上升，在 顶部积聚并逐渐下沉(2)小玻璃罩中蜡烛燃烧对 周围空气温度的影响(3)大玻璃罩中蜡烛燃烧时， 产生热的二氧化碳上升，到一定高度后冷却，由于二 氧化碳的密度比空气大从周围下沉，导致玻璃罩底 部二氧化碳积聚并逐渐上升，所以B组实验低处烛 焰先熄灭 26.(1)温度氢氧化钠溶液浓度(2)温度越高，电解 水的速率越快(3)A 27.(1)4水(2)种子萌发消耗氧气，产生的二氧化碳 被氢氧化钠溶液吸收，使大烧杯内气压变小，大气压 将水槽中的水压入大烧杯内 (2) ◆A MimmmmhnN R 29.(1)产生大量白烟10(2)先向右后向左6 30.(1)水汽输送⑤(2)纬度越高，人均水资源拥有 量越少 31.(1)A(2)C(3)变小 32.(1)氯化钠根据氯化钠的溶解度，在20℃时，饱和 氯化钠溶液的溶质质量分数=36g/(36g+100g) ≈26.5%，26.5%<30%，质量分数达不到30%，所 以不可能是氯化钠。(2)设需要加水的质量为x, 30g×30%=(30g十x)×10%,x=60g。 暑假综合练习十五 1.C解析：目前地球上可以被人类利用的淡水主要包 括湖泊淡水、土壤水、河水及分布较浅的地下淡水等。 2.B解析：溶液可以有颜色，如硫酸铜溶液为蓝色。 3.D解析：通过水循环示意图可知，自然界中的水总 量不变，但可供人们利用的淡水资源很少，且分布不 均匀，我们必须节约用水。 4.C解析：①氢气填充气球，利用氢气密度比空气小 ·89·快乐假朗 月 暑假综合练习十二 I.用适当的冠词填空（如不需要填“/”）。 1.There is market near our school. market is very large. 2.You missed “S”is word“discuss”. 3.This is empty bottle.Could you give me full one? 4.-Can I see menu first? -Yes,of course. 5.-Are you Chinese or Japanese? -Chinese.But I was born in Japan. 6.After school we usually play basketball for an hour on playground. 7.-What's behind door?I can't open it. -Let me see.Oh,there is chair. 8.We are in same class. 9.Your football socks are under table.Please put them away. 10.We can't put basket in car.It's full. Ⅱ.阅读理解。 根据表格中的内容，为后面各题选择正确的答案。 How did they spend their vacation? I went to Singapore for my vacation.I lived with my uncle's family.They live Kevin in Singapore.It was sunny most days.I visited many places and ate many kinds of food.They were nice. I spent my vacation in Paris.I had a great time there.The beaches were Ruth beautiful and the weather was OK.I had lots of delicious food.People there were friendly. I didn't enjoy my vacation.The bus trip was boring.After I arrived in the city,it rained almost (every day,so I stayed at the hotel for six days. Bob On the last day,I went shopping.But the shops were crowded and things were expensive. )11.When Kevin visited Singapore,he lived in A.a hotel B.many places C.his uncle's house ( )12.“It was sunny most days..”means(意思是)“ ” A.Sometimes it was sunny B.Sometimes it rained C.It was sunny every day ()13.In Ruth's eyes,Paris was A.great B.not good or bad C.awful ·48· 暑假作业·七年级 )14.Perhaps(也许)Bob stayed in the city for days. A.six B.seven C.eight )15.Bob thought his vacation was A.relaxing B.expensive C.terrible Ⅲ.补全对话。 根据对话内容，从方框中选出5个合适的句子补全对话。 A:How was your vacation,Li Lei? B:16 I went to Beijing with my parents. A:Cool!Where did you go in Beijing? B:We went to the Summer Palace,the Palace Museum,the Great Wall and so on. A:17 B:It's interesting.I really like the Palace Museum.It has many beautiful things from dif- ferent dynasties(朝代). A:18 B:Yes,I did.I saw a boy dancing on the Great Wall.19. A:Wow,that's great!Can you show me the photos? B:Sure.20. A.Did you see any intresting people? B.What do you think of Beijing? C.What does the dancing boy look like? D.I will bring them to school tomorrow. E.It was great！ F.And I took some photos with him. G.I went there by plane. 知识博览 Simple oral English in movies 同学们，你们喜欢看外文电影吗？一起来学习电影里面经常出现的简单口语吧！ Listen! 一听着！ Anytime! 随时吩咐 Now! 现在就做！ After you. 您先。 Present! 到（有）！（用于，点名时） About when? 大约何时？ Please! 拜托了！ Allow me! 让我来！ Really? 真的？ Bingo! 中了！ Relax！ 放轻松！ Boring! 真无聊！ Right！ 对的！ Crazy！ 疯了！ Soso! 马马虎虎！ Deal！ 一言为定！ Fifty-fifty！ Someday！ 改天吧！ 对半分！ Speaking! 一（打电话时)我就是！ Fresh! 好有型！帅！ Sure！ 当然！ Gone! 跑了！ Try! 去试一下！ Indeed? 真的？ Wait! 等一等！ Liar! 你撒谎！ Wel?-—怎么样？ 。49·