A:打破了人类长期以来相对隔绝的状态
B:此前从未出现大规模的远航活动
C:宣扬了罗马教廷的声威
D:巩固了西欧的封建制度
我国东海钓鱼岛经常刮大风,岛上生存着许多无翅或残翅的昆虫,对这一现象的正确解释是( )
Housing prices ________ since the end of the last year. Therefore, it's time the central government ________ some effective measures to bring them under control.