①画出△ABC关于x轴对称的△A1B1C1,
②画出将△ABC绕原点O按逆时针旋转90°所得的△A2B2C2,
③△A1B1C1与△A2B2C2成轴对称图形吗?若成轴对称图形,画出所有的对称轴;
④△A1B1C1与△A2B2C2成中心对称图形吗?若成中心对称图形,写出所有的对称中心的坐标.
②如图所示;
③△A1B1C1与△A2B2C2成轴对称图形,对称轴如图所示;
④△A1B1C1与△A2B2C2成中心对
改错题。句子中有一处是有错误的,把它找出来并改正。
①There are many people are playing basketball there.____ ②Could you tell me the different between the two books.____ ③It was my grandpa's eighty birthday yesterday._____ ④Bady,it's very lazy for you to sleep late every morning.____ ⑤I wrote an 800-word's composition yesterday.____ ⑥The fish we caught is still living.____ ⑦The Great Wall is one of the most famous building all over the world.____ ⑧If Tom will study hard this term,he will catch up with his classmates.____
商店罐头的盖子上都有一个“真空安全钮”上面写着“若真空安全钮浮起,请勿购买”若罐头的瓶盖很难拧开.如图所示.用螺丝刀把瓶盖撬起一个缝隙,瓶盖就很容易被拧开,关于此过程涉及的物理知识.下列说法正确的是( )