不一定在三角形内部的线段是( ) (A)三角形的角平分线 (B)三角形的中线 (C)三角形的高 (D)三角形的中位线 答案:C根据句意和中文提示完成下列句子。1. —Is that a ______ (电子游戏)? —Yes, it is. 2. Please ______ (打电话) me at 666-8899. 3. —______ (请原谅), Anna, is this your English book? —Yes, it is. 4. Look at the ______ (失物招领). Is that your watch in it? 5. ______ (怎样) can you spell the word "key"?