墓地供电工程的维护是保证墓地电能正常供应所采取安全管理、正常运行管理、供电设备的维护管理等一系列的管理工作。
参考答案：对
阅读理解，根据内容判断正(T)误(F)。
Thompson: Jack, I have a riddle. Can you guess?
Jack: OK. What's it?
Thompson: Please tell me who he is: He is not my brother, and is not my sister, but he is a child of my parents.
Jack: I don't know.
Thompson: Ha-ha, it's very easy. It's me.
( ) 1. Thompson has a riddle.
( ) 2. Jack can guess the riddle.
( ) 3. This riddle is very difficult.
( ) 4. Jack can't answer Thompson's question.
( ) 5. The answer of the riddle is "Thompson".
多根牙阻抗中心的位置，正确的是（）
A.在根分叉附近方向1～2mm处
B.在根分叉附近往根尖方向1～2mm处
C.在根分叉附近往根尖方向3～5mm处
D.在根分叉附近往方向3～5mm处
E.以上都不对
方向1～2mm处