题目

阅读 Taking notes is very important in high school. If you don't take notes, youmay find it difficult to go over the lessons. You need to get some skillsin order to take perfect notes. Here are some tips to help you.Try not to overdo it. Some students like writing down every word. Ifyou want to write down every word, you may miss the most important points. Somepeople learn well by listening carefully, writing down a few key points, andthen going over the material after class when they have more time. So just makesure that you've written down the most important points. Ask your teacher to 如图，四边形ABCD内接于⊙O，若它的一个外角∠DCE=70°，则∠BOD=    ．