1.A lot of houses collapsed in the earthquake because of u constructions.
【答案】 unstable
2.Floods are not u these days;they happen more and more often.
【答案】 uncommon
3.Volcanic e and earthquakes have always been a threat in certain parts of the world.
【答案】 eruptions
4.Armed c could start at any time.The world is not peaceful at all.
【答案】 conflict
