人孔是为操作人员进、出油罐进行()、清罐而设置的,同时兼有通风、采光作用。
A、清淤
B、防腐
C、检修
D、计量
参考答案:C
—What were you doing when the rock star arrived?
— .[ ]
A. I was doing my homework
B. I am doing my homework
C. I do my homework
D. I did my homework
人文地理学研究的主要哲学方法论主要包括()。