磁力线离开和进入工件表面形成的磁场称（）。
A.磁场
B.磁路
C.漏磁场
D.磁痕
参考答案：C
根据汉语提示填入正确的单词。
1. Students in Xinjiang go to school from _________ (四月) to _________ (九月).
2. June _________ (一日) is Children's Day. All the children are very _________ (高兴).
3. The _________ (老的) man is _________ (九十) years old now.
三催化外取热器的催化剂由（）控制
A、提升风
B、单动滑阀
C、双动滑阀
