【简答题】java中的字符输出流都是抽象类 的子类。
【单选题】The disappearance of jobs is a __________ of a deeper socio-economic change.
【单选题】The socio-economic conditions are not readily amenable to change, interrelated as they are with culture, mores and national capacity for development.
【单选题】Desertification is a serious environmental and socio-economic problem at present.