∵MN垂直平分BC,∴BD=CD,故答案为BD=CD. (2)如图2中,证明:①∵E为AB的中点,∴AE=BE.又∵DE=EF,∴四边形AFBD是平行四边形. ∴AF∥BD,AF=BD.由(1)得:BD=DC,∴AF∥DC,AF=DC.∴四边形AFDC是平行四边形. ②∵∠BAC=90°,BD=DC,∴AD=1212BC=DC.由①可得:AF=DC,∴AF=AD. 点评 本题考查...
mn是锰的元素化学符号。锰是一种灰白色、硬脆、有光泽的过渡金属,原子序数为25。它在工业领域和生物体内都起着重要作用,主要用于激活和构成酶,催化多种生化反应。
在淘宝,您不仅能发现日本ZEBRA斑马彩色自动铅笔MN5男女小学生用安全专业活动铅笔0.5按动式透明自动笔写不易断清新小儿童文具的丰富产品线和促销详情,还能参考其他购买者的真实评价,这些都将助您做出明智的购买决定。想要探索更多关于日本ZEBRA斑马彩色自动铅笔MN5男女小
(2)与(1)证明方法一样可得到△ACM≌△CBN,根据全等的性质得AM=CN,CM=BN,而MN=CN-CM=AM-BN. 解答:(1)证明:∵AM⊥PQ于M,过B作BN⊥PQ于N, ∴∠AMC=∠CNB=90°, ∴∠MAC+∠ACM=90°, ∵∠ACB=90°, ∴∠ACM+∠NCB=90°, ∴∠MAC=∠NCB, ...
of the Mn-Bi-based alloy for vapor deposition is composed of 50-85wt% Bi, <=3% Al, <=500ppm Ca, <=300ppm O, <=30ppm N and the balance substantially Mn and is incorporated therein with <=5% Cr at need. Such alloy contains O and N at the lower ratio and in addition, the ...
MnO-4中Mn的化合价为+4价A.正确B.错误的答案是什么.用刷刷题APP,拍照搜索答疑.刷刷题(shuashuati.com)是专业的大学职业搜题找答案,刷题练习的工具.一键将文档转化为在线题库手机刷题,以提高学习效率,是学习的生产力工具
Packwood’s comments are significant because opponents of the welfare initiative approved by House Republicans had hoped that the Senate would reject some of its more contentious elements, including removal of entitlement status. Advertisement The House measure would consolidate AFDC and other guaranteed ...
解答解:∵|m-3|与(2+n)2互为相反数, ∴|m-3|+(2+n)2=0, ∴m-3=0,2+n=0,解得m=3,n=-2, ∴mn=3-2=1919. 故选C. 点评本题考查的是非负数的性质,熟知任意一个数的偶次方和绝对值都是非负数是解答此题的关键. 练习册系列答案 ...
∵MN⊥x轴,所以由ON=MN可知,△MNP为等腰直角三角形; 如图2,当M运动到第三象限时,要MN=MP,且PM⊥MN, 设点M(x,2x+3),则有:-x=-(2x+3), 解得:x=-3, 所以点M坐标为(-3,-3). 若MN为斜边时,则∠ONP=45°,所以ON=OP,设点M(x,2x+3), ...
【题目】如图所示,在一磁感应强度B=0.5T的匀强磁场中,垂直于磁场方向水平放置着两根相距为L=0.1m的平行金属导轨MN和PQ,导轨电阻忽略不计,在两根导轨的端点N,Q之间连接一阻值R=0.3Ω的电阻,与导轨垂直放置着金属棒ab,其电阻r=0.2Ω,当金属棒在水平拉力作用于以v=4.0m/s向左做匀速运动时( ) ...