品德不良学生有哪些特点？
联合国HDI的中文含义是（），用来评估和比较世界不同国家不同时期在健康、知识和收入三个重要领域的进步。 ["A.国民生产总值","B.国家发展指数","C.社会发展指数","D.人类发展指数"]
In an open lifeboat，the lifeboat compass is usually（）. ["placed in a fixed bracket when being used","clamped to any position convenient for the coxswain to see it","permanently mounted on the lifeboat's centerline","mounted in the center of the boat to eliminate deviatio"]
售房单位未办妥《土地使用权证》、《房屋所有权证》，抵押人应会同贷款行持依法生效的（）办理抵押登记备案手续。 ["他项权证","房屋买卖合同","房产证","土地使用权证"]
在市场经济条件下，经济人最基本的天性就是（） ["机会主义","自由主义","损人利己","竞争逐利"]
开展维修工作前后必须采取哪些措施？
