如图，△ABC中，∠ACB为钝角．按要求解答下列问题：（1）在图中画出△ABC的AC边上的高BD（在图中相应点处标出D）；（2）在CB上截取CE=CD（在图中相应点处标出E），画直线DE；（3）若∠A

更多内容推荐

• 完形填空。 April Fool's Day April Fool's Day is a western festival. No one1 exactlywhen and how
• Today, bicycles are elegantly simple machines that are common around the world. Many people ride bic
• Details of the latest James Bond film Skyfall have been shown to the public. It comes 50 years to th
• It was a simple letter asking for a place to study at Scotland’s oldest university which helped star
• 在距今1200多万年前，森林古猿曾广泛分布于、、地区，尤其是的热带丛林。-七年级生物
• 三角形一边上的中线把三角形分成的两个三角形的面积关系为（）．-七年级数学
• Japanese sailor Kenichi Horie has finished a 110-day solo (单独的) voyage across the Pacific Ocean in a
• Every year thousands of tourists visit Pompeii, Italy. They see the sight that Pompeii is famous for
• Towards the end of Middle English, a sudden change in pronunciation started, with vowels being pron
• 对森林古猿进化成人类的叙述不正确的是（）A．由于森林的大量消失，使部分森林古猿不得不下地生活B．下到地面上生活的森林古猿，其身体向直立行走方向发展C．森林古猿之间在下地之-八年级生物
• 在△ABC中，AD是BC边上的中线，若△ABD和△ADC的周长之差为4（AB＞AC），AB与AC的和为14，求AB和AC的长．-七年级数学
• As is known to us all, baths and bathing have long been considered of medical importance to man. In
• The French Revolution broke out in 1789. At the time France was in a crisis. The government was badl
• The earliest newspapers started in ancient Rome. They were handwritten news sheets. The first printe
• 人类从哪里来？我们每一个人又是怎样来到世界上的呢？以下是“人的由来”的相关概念图，请根据图中提示回答有关问题。（1）在A、B两处填入恰当的词：A、B（2）B的形成发生在内，胎儿是-七年级生物
• 把△ABC分成面积相等的两部分，把△DEF分成面积相等的四部分．-七年级数学
• To take the apple as a forbidden fruit is the most unlikely story the Christians（基督教徒）ever cooked up
• Many of the people who appear most often and most gloriously in history books are great conquerors a
• 直立行走使古人类能（）A．扩大活动范围B．便于手肢行走C．使前肢解放，便于使用工具D．便于从树上摘果实-八年级生物
• 画△ABC中AB边上的高，下列画法中正确的是[]A．B．C．D．-七年级数学
• 如图所示，在△ABC中，点E为AC上一点，BE⊥AC，则以BE为高的三角形有[]A．3个B．4个C．5个D．6个-七年级数学
• 下列哪项不是人类开始起源的环境条件A．气候由温暖湿润变得干旱寒冷B．气候由干旱寒冷变得温暖湿润C．连绵不断的森林变得稀疏D．稀树草原取代森林的面积扩大-八年级生物
• San Francisco has its cable cars． Seattle has its Space Needle． And, Longview has its squirrel bridg
• To many Americans，Labor Day(劳动节) marks the end of the summer，a day off from work and school，and one
• Since the beginning of time, man has been interested in the moon. The Romans designed a special day
• Roman Pantheon （万神殿） is one of the greatest achievements of the ancient Romans. The ancient Romans w
• 人类学家把下列哪一项作为人与猿分界的最重要的标准之一（）A．下肢增长B．直立行走C．骨盆变短增宽D．脊柱由弓状变为“S”形-八年级生物
• Barcodes (条形码) aren’t given much thought by the majority of consumers, but these codes were fairly r
• 直角三角形的三条角平分线交点在[]A．三角形外B．三角形内C．直角顶点处D．斜边上-九年级数学
• 如图，△ABC中，∠B=40°，AC的垂直平分线交AC于D，交BC于E，且∠EAB：∠CAE=3：1，则∠C等于[]A．28°B．25°C．22.5°D．20°-七年级数学
• 人类和现代类人猿都起源于森林古猿。()-七年级生物
• 现代类人猿和人类的共同祖先是A．类人猿B．古猿C．黑猩猩D．长尾猴-八年级生物
• San Francisco has its cable cars. Seattle has its Space Needle. And, Longview has its squirrel bridg
• Science, as we think, was born when the Greek philosopher ( 哲学家 ) Thales ( about 640-546 B.C.) asked
• Before Alaska became part of the U.S., it had been owned by Russia. Trading posts and small settlem
• Nowadays more and more young athletes are taking part in the risky activities called “extreme sports
• Medalists of the 1948 London Olympic Games look back on their summer of victory.SAMMY Lee, 91, U.S.
• 下列关于人类由来的叙述正确的是（）A．人类具有动物的基本特征，所以人与动物没有根本区别B．环境的变化使类人猿进化成人C．所有的森林古猿都适应了生存环境D．劳动在从猿到人的进-八年级生物
• 古人类能够很好地交流与合作，这是由于（）A．直立行走B．制造工具C．产生了语言D．火的使用-八年级生物
• 能把三角形的面积平分的是[]A．三角形的角平分线B．三角形的高C．三角形的中线D．以上都不对-七年级数学
• 如图，已知∠ABC、∠ACB的平分线相交于F，过F作DE∥BC交AB于D，交AC于E．BD、CE、DE之间存在怎样的关系？说明理由．-七年级数学
• 下列关于人类起源与进化的叙述中，正确的是（）A．人类的祖先是森林古猿B．现代类人猿与人类没有共同祖先C．人类进化过程是人为控制的D．人类进化过程与自然选择无关-八年级生物
• 三角形的角平分线、中线、高线中[]A．角平分线是射线，其余的是线段B．高是直线，其余的是线段C．高是直线，角平分线是射线，中线是线段D．每一条都是线段-七年级数学
• For thousands of years, the most important two buildings in any British village have been the church
• In the 19th century, Americans from the eastern states moved out west to settle in the rich new land
• 下列属于观点，而不一定是事实的是A．人和现代类人猿有众多相似点B．现代类人猿和人类的共同祖先是森林古猿C．古人类化石“露西”是在非洲发现的D．除非洲外，其他地方没有发现200-七年级生物
• There are fifty states in the United States. The largest in population is California,the largest in
• 下列与人类亲缘关系最远的动物是（）A．长臂猿B．猕猴C．猩猩D．黑猩猩-七年级生物
• “We do look very different; we’re older. Leo’s 38, I’m 37. We were 21 and 22 when we made that film.
• 能够用火是人类与动物的一个重要差别，使用火对人类进化的重要意义是()A．用火来驱赶猛兽B．用火来攻击敌人C．用火来御寒D．用火来烧烤食物，改善了身体的营养，有利于脑的发育-七年级生物