在△ADE和△CFE中，:AE=CE,∠1=∠2，DE=FE,AADE≌人CFE∠A=∠ECF,AD=CFCF∥AB.BD=AD,.CF=BD.四边形DBCF是平行四边形（一组对边平行且相等的四边形是平行四边形).D∥BC(平行四边形的定义)，DF=BC...

Unit 6 Ihe animal kingdom Lesson 17 Interesting animals (reading)PenguinsGiraffesbodybodybig9以：☆☆headsmallsmal山necklegsshorrthin:女☆☆★spreadneckshortlongGbendevesbig试讲稿U...