题目

已知如图：AD∥BC，E、F分别在DC、AB延长线上．∠DCB=∠DAB，AE⊥EF，∠DEA=30°． （1）求证：DC∥AB． （2）求∠AFE的大小． 答案：【考点】平行线的判定与性质． 【分析】（1）根据平行线的性质得出∠ABC+∠DAB=180°，求出∠ABC+∠DCB=180°，根据平行线的判定推出即可； （2）求出∠EAF和∠AEF的度数，即可求出答案． 【解答】证明：（1）∵AD∥BC， ∴∠ABC+∠DAB=180°， ∵∠DCB=∠DAB， ∴∠ABC+∠DCB=180°， ∴DC∥AB； （2）解：∵DC∥AB，根据括号内的英(汉)语提示,完成句子。(每题1分,共10分)【1】The teacher told us that the earth ____ (go)around the sun in the east.【2】They ____(帮助) us with English last night.【3】He fell asleep while he _____ ( watch)TV.【4】A good beating will teach you to tell the ____ ( true) in future.【5】Please ____ (允许) me to go shopping with you.【6】Education is one of the most important parts of a country’s _______ (develop)【7】The ____ ( die ) of my cat made me feel sad.【8】It’s too hard for me to learn it. Can you show me how ____ （swim）.【9】It’s snowing _____ ( heavy). Let’s stay at home.【10】Why not _____(visit) your grandparents?