一字起头的成语

错的这道题怎么简算? 请问这两题脱式怎么做?能简算的要简算!急用! 如图,已知在△ABC中,∠A=90°,AB=AC,∠A的平分线与AC交于点D过点C作CH⊥BD,H为垂足试说明BD=2CH如图，已知在△ABC中，∠A=90°，AB=AC，∠B的平分线与AC交于点D过点C作CH⊥BD，H为垂足试说明BD=2DH 已知,三角形ABC中,角A=90度,AB=AC,BD平分角BAC,CH垂直BD,说明BD=2CH 如图,已知点B,C,D在同一条直线上,三角形ABC和三角形CDE是等腰三角形,BE交AC于F,AD交CE于H,求证CF=CH. 一道英语选择题,题目如下：——What did the teacher say just now?——She told me______I got high marks in the English test.A.where B.that C.whether D.what请哪位说明一下这道题为什么选 B ,谢谢. 一道英语选择题.如下.－－Do you know when he ______ back －－Sorry ,I don”t .When he _______back ,I”ll tell you .A.comes ; comes B.comes ; will comeC.will come ; comes D.will come ; will come我选的是A,我知道下面一句用到 x^2+3x-(a^2+a-2),求因式分解, 用初二的方法 因式分解(x*x+3x+3)(x*x+3x-4)+6 因式分解x^3-3x^2+4,最好有思路和过程．在线等． x^3-3x+2怎么因式分解成（x-1）^2(x+2)【求过程】 简算方法96000除125除8 excel表格内输入数字出现特殊符号?请问怎么设置?比如说别个的表格已经做好了,我在其中一个表格中输入数字,但是保存后出现的是乱码? 如图,在三角形ABC中,AD平分角BAC交BC于点D,角ABC,角ACB的角平分线交AD于点O,过点O作OE垂直于BC于点E试判断角BOD与角EOC是否相等sorry，图传不上去 如图三角形ABC中,角ACB=90度,角平分线AD与高CH交与F点,DE垂直AB于E,求证:四边形CDEF是菱形. 用商不变的性质计算 化简比是应用了 （） A.商不变的性质 B.分数基本性质 C.比的基本性质? 利用商不变的性质简算560÷35 3．9÷26 2．87÷0．25=560÷（5×7） =3．9÷（ ）÷（ ）= ÷（0．25×4）=560÷7 = = = = = 符号 度 分 秒 的关系 He got up early ( ) he could catch the early bus .A.because B.so that C.when D.whetherMy young brother couldn't work out the answer and ( ).A.so could I B.nor could I C.so can I D.nor I could 如图 在rt三角形abc中 角c等于90度,沿过b点的一条直线be折叠这个三角形已知：如图，在Rt△ABC中，∠C=90°，沿过B点的一条直线BE折叠这个三角形，使C点与AB边上的一点D重合。当∠A为多少时， ( )9.Are there ____ animals ____ the farm?（A还是C?）A.many kinds … on B.a kind of … at C.several kinds of … on D.several kind of … in( ) 8.He hoped ________ doing his homework soon.（B还是D?）A.his son to finish B.to finishC.finishin 一些有趣的英语选择题1.They went to the rice fields to help the farmers ________their old clothes.A.put on B.wear C.in D.wear in 2.----No one believes what you told us yesterday.It's too surprising--------___________,that's the truth.A.Then 所有选择题答案,英语好的进 word2007中正负号和分秒符号怎么输入 word2013 插入分秒符号 用因式分解法解方程[2x-1][3x+4]=2x-1(2X-1)(3X+4)=2X-1(2X-1)(3X+4)-（2X-1)=0(2x-1)(3x+4-1)=0(2x-1)(3x+3)=0x1=1/2x2=-1第三部3x+4为什么-1 已知,如图,在Rt三角形ABC中,角ACB等于90度,CD是三角形ABC的角平分线,DE垂直BC,DF垂直AC,垂足分别为E,F,求证,四边形CEDF是正方形 1.Nobody noticed the thief slip into the house because the lights happened to ___A.be put up B.give in C.be turned on D.go out 2.The new bridge __ by the end of last month A.has been designed B.had been designed C.was designed D.would be designed3.Wh 要原因）The new shop has taken away most of my_____(custom) 1.Uncle Tom is headmaster of the school in our District.(同义句)Uncle Tom______ ______ ______of the school in or district.2.Mike wouldn't like to stay at home.Neither would Mary.Mike wouldn't like to stay at home,Mary_______,______. 要原因）1.It was a pity that you____(not attend)the meeting last Friday afternoon.2.The____(high)you climb ,the more beautiful view you will see.3.It rained heavily last night,so I didn't go out.(改为同义句)I didn't go out last night______ _