题目

将一副三角板如图放置，使点A在DE上，BC∥DE，则∠ACE的度数为__________． 答案：【答案】15°【解析】试题解析：∵BC∥DE，∴∠BCE=∠E=30°，∴∠ACE=∠ACB-∠BCE=45°-30°=15°.To do a bit for the motherland, ______. 　　A. working hard is necessary     　 B. to learn a foreign language is needed 　　C. it is important to master science D. one should serve the people whole-heartedly