教师必须十分重视自身的发展,做到以身作则,为人师表,这体现了教师劳动的哪一特点 ( )
A.复杂性、创造性
B.连续性、广延性
C.长期性、间接性
D.主体性、示范性
参考答案:D
— Why did the police ______the crowd?
— Because the president' s car ______in the street.[ ]
A. break down; broke down
B. break up ; broke up
C. break down ; broke up
D. break up; broke down
请简述向炉内加盐的缺点?