After school, we usually play ______ basketball for half ______ hour on the playground.
A:the; /
B:the; the
C:/; an
D:/; a
读“欧洲西部地图”,完成下列各题。
香港最大的进出口贸易伙伴是( )
327+251=____
如果三角形的三个内角的度数比是2:3:4,则它是( )