液压牵引采煤机常用的主油泵有斜轴式、通轴式和（）轴向柱塞式。
A.单轴式
B.多轴式
C.直轴式
参考答案：C
Hi! My name is Zhou Mei. I’m your English(英语) teacher. I’m from Beijing. This is Mike. He’s from the U.S.A. He’s your teacher, too. This is Li Lei. He’s from Guangzhou. He’s new(新来的).
根据短文内容，判断正(T)误(F)。
小题1: Zhou Mei is a teacher.
小题2:Mike is a teacher, too.
小题3:Zhou Mei and Mike are from China.
小题4: Li Lei is new.
小题5: Li Lei is from Beijing.
图7是某区域某时地面天气简图。读图回答2小题。
小题1:图中M地的风向是
A．东北风
B．东南风
C．西北风
D．西南风小题2:产生图示区域降水的天气系统是
A.气旋 B反气旋 C. 暖锋 D.冷锋
