题目

Welcome to Sight Word Tales-the fun, motivating way to learn sight words! These delightful stories teach the top 100 Dolch words-long recognized as the most important words to learn in order to form a basis for reading success-all in an appealing, engaging context. ① What are sight words? Reading research shows that 50 to 75 percent of text is made up of common, repeated words. Knowing these words by sight-that is, being able to recognize them immediately and without thought-greatly increases reading fluency and comprehension. The Sight Word Tales program includes the 100 most frequently re如图，在⊙O中，D、E分别为半径OA、OB上的点，且AD=BE．点C为弧AB上一点，连接CD、CE、CO，∠AOC=∠BOC．求证：CD=CE．