中国大学MOOC: Which of the following disaster are natural disasters?
                    举一反三
- 中国大学MOOC: Which of the following is not considered as a natural disaster?
 - Which of the following is the subject of disaster films?( ) A: man-made disasters B: love C: natural disasters D: wars
 - Which of the following disaster are natural disasters? A: variation B: avalanche C: flood D: volcanic eruption
 - Which of the following is the subject of disaster films? A: A. natural disasters B: B. man-made disasters C: C. love D: D. wars
 - 中国大学MOOC: Which of the following disaster is man-made disaster?
 
