②由AC平分∠BAD,AD∥CE,可得AE=CE,
综合①②可得四边形AECD是菱形,
③由∠ACE=∠EAC,∠ECB=∠B和△ABC内角和180°,可得△ABC是直角三角形,
④由菱形AECD和E为中点,可得S△AEC=S△ACD=S△BEC=3,
∴
如图1所示,用A、B两把刻度尺测量同一物体长度,放置正确的是____刻度尺,其分度值是____,该物体的长度为____cm.图2秒表的读数为____s.
走进化学实验室,同学们学会了最基本的操作,以下操作正确的是
阅读短文,判断句子正(正确)误(错误)。
Tom is my classmate. He is from London in England. But he likes China very much. Now he is in Beijing. He is a little fat. He has a round face and big blue eyes. His hair is not black but yellow. His nose, mouth and ears are big. He likes blue. He likes wearing a blue T-shirt and blue jeans. Look at his hand. He has a football in it. We often play football after class.
国家要繁荣、民族要振兴,需要我们每个公民加强修养、提高素质、掌握科学文化知识。这说明受教育( )