我国是世界上季风气候最显著的国家之一,其原因是( )
A:纬度位置的影响
B:海陆位置的影响
C:地形复杂多样
D:地势西高东低
——I can hardly believe my eyes. Is that you, Lucy?——Yes. It has been almost 20 years______ we were together.
下列不属于隋的贡献的是( )
下列物质属于纯净物的是 ( )