汽机油系统事故排油阀其操作手轮应设在距油箱5m以外的地方。
参考答案:对
-What does your mother do?
-_____________[ ]
A. She is a teacher.
B. She is fifty.
C. She likes reading.
D. She works in a hospital.
大多数国家的高等学校可分为三个层次,分别是:()、大学和专门学院、()。