为了提高热机效率,可采取的措施是( )
A:采用热值高的燃料
B:降低热机功率
C:保证良好的润滑,减小摩擦
D:以上措施都可以
— What do you think of your teacher?
— He is very kind. He always the students his own children.
从纬度位置看,欧洲大部分地区位于( )