如图,某电信部门计划修建一条连接B、C两地的电缆.测量人员在山脚A点测得B、C两地的仰角分别为30°、45°,在B地测得C地的仰角为60°.已知C地比A地高200m,电缆BC至少长多少米(精确到1m)?
解:过B点分别作BE⊥CD、BF⊥AD,垂足分别为E、F.
设BC=xm.
①矛盾的同一性是相对的,斗争性是绝对的
②在砥砺自我中走向成功
③量变和质变是事物变化过程中两种不同的状态
④矛盾普遍性寓于特殊性之中
请以“那个为我提灯的人”为题,写一篇不少于600字的文章。
要求:①内容具体,有真情实感;②除诗歌外,文体不限;③不得出现真实的人名、校名;
小羊“多莉”的成功培育,说明遗传物质主要存在于( )
I have1good friend and his name is Jack. Here are his2about his life in twenty years. Jack will be a policeman in twenty years because he thinks it's an exciting job. He will live and work3Beijing, because it's a very beautiful city and he likes it very much. He4taller and stronger and he will have short straight hair. In his free time, he will play5sports to6. He will play tennis every day and he will go swimming and skating on weekends. He will7smart clothes like uniform. Jack will have a happy family. Maybe he will have two8. They will be lovely and cute and he will love them very much. Now he9and tries his best10his predictions come true.