2022-10-15
12.A【解析】∵x}=y1ny,不妨设nx=my=,令fx)=lnx,x∈(0,4],则函数y=f(x)的图象与直线y=t有两个不同的交点,f(x)1-Inf(x)>0,f(x)单调递增,当x∈(e,4]时,f(x)<0,∫(x)单调递减,又ln2_ln4,故2≤x; ˂e˂y≤4xn1=2(n-1),又xn˂c且(xn)max→c,故3xn˂3c且(3xn)mx→3e,
2022-10-15
15.(共17分)(1)向上层清液中继续滴加BaCl2溶液,无白色沉淀生成,(2)AgNO3溶液(3)坩埚(4)40w233(7)b(8)迦侣(5)偏低(6)检查装置气密性abd×106525×10(9)偏高(10)否 1,B【解析】a<0…a>b,故A对;a ˂b0,;0˂-b,a˂a-b 1,故B错;ab<0,…一a>-b>0,即|-a|&g
2022-10-15
8.C【解析】土壤小动物形体微小,活动能力强,不宜用样方法和标志重捕法进行调查,可用取样器取样法调查丰富度,A项正确;统计丰富度的方法有记名计算法和目测估计法,对个体较大、种群数量有限的群落一般用记名计算法进行丰富度的统计,B项正确;土壤小动物具有趋暗趋湿、避高温的习性,C项错误;可以使用放大镜或实体镜对土壤小动物进行观察,D项正确。 3.C【解析】盐酸和酒精配成解离液,目的是使细
2022-10-15
读后縷写【参考范文】We made up our minds to save the nurse with him together.We were faced with falling rubble from time to time. The trappednurse was still alive. We focused our efforts on removing thebri
2022-10-15
7.[答集]B[解析]从“石演”可以联想到“碳”和“石炭酸”根据“石演”燃烧现象可知其为煤,A高温选项正确。“石炭”燃烧时“泼水”将发生C+H,O=CO+H高温2CxHy+2cH2O=2rCO+(2x+y)H2等反应,B选项错误,C选项正确。煤干馏产物之一煤焦油中含有酚类(如苯酚即石炭酸),D选项正确,故选B 20.解:(1)因为a=√6+2,△ABC的外接圆半径R为2,所以sin
2022-10-15
第二节读后续写( One possible version)Finally, the day came. Anxious but excited, I spent the whole day cleaning the house andpreparing the food. With everything ready, all guests arrived one by one. wit
2022-10-15
二、读后续写范文(满分25分)Possible version 1Paragraph 1:It was time to put an end to the Magic Marty show. I walked over. "It was fishing line. " I sneeredfolding my arms. Marty subconsciously fingered the
2022-10-15
20.(1)圆底烧瓶(1分)饱和食盐水(1分)(2)水浴加热(1分)Cl2+2OH=ClO-+C+H2O(1分)避免生成NaCO2(1分)(3)吸收尾气(1分)AC(1分)(4)过滤(1分)少量(冷)水洗涤(1分)(5)紫(1分)小于(1分)【解析】(1)根据盛放MnO2粉末的仪器结构可知,该仪器为圆底烧瓶;装置a中盛放饱和食盐水除去氯气中混有的HCl气体(2)根据装置图可知,盛有KOH
2022-10-15
25.(1)根据I-t图象可知I=k1(k1=2A/8)(1分)当=2s时,回路中电流I1=4A(1分)代,根据欧姆定律E=1R=2v(分)口(2)流过回路的电荷量q=(1分)每意,1=1(1分),的两面干大kit解得2(1分)则A,的当当t=2s时,q=4C(1分)要,由欧姆定律得I=(1分)=rtan45°(1分)、顶,里的根据B-x图象可知,B=(k2=1T·m)(1分)解得v=5
2022-10-15
6.C【解析】放电时,a极为负极,b极为正极,负极反应式为Li-e-Li·,正极反应式为O2+2H2O4e=4OH”,L向b电极迁移得到LiOH溶液,A、D项正确;放电时,a极电势比b极电势低,B项正确;没有指明气体所处的状况,无法计算生成O2的体积,C项错误 17D〖【解析】植物乙与植物甲存在生殖隔离,属于不同物种,所以不属宇一个种群;植物乙与植物甲能杂交,但产生的是三倍体,三倍
2023-04-05admin
2023-04-05admin
2023-04-05admin
2023-04-05admin
2023-04-05admin
2023-04-05admin
2023-02-24admin
2023-02-24admin
2023-02-24admin
2023-02-24admin
扫码二维码
获取最新动态
