马克思地租理论认为，土地自然条件的差别是( )产生的条件。
A．绝对地租
B．级差地租
C．垄断地租
D．城市地租
参考答案：B
根据句意, 用括号中所给词的正确形式填空, 每空不限一词.
1. The police believe these footprints are one of the _____________ (thief).
2. The man in his _____________ (forty) is the person who saved that boy.
3. The old man said that he __________ (lie) in bed from eight to ten last night．
4. No country _________ (make) such great progress as China in the past thirty years.
5. All the students _____________ (divide) into four groups and then they went on hiking with four
teachers.
空压机的拆卸注意事项有哪些？
