1992年,联合国教科文组织主张以“两个大陆相遇500年”为主题,举行哥伦布航抵美洲纪念活动。“两个大陆”分别指的是( )
A:美洲和非洲
B:欧洲和美洲
C:欧洲和亚洲
D:亚洲和非洲
质量为6×103mg可能是( )
A man says to his friend,"Guess how many coins(硬币) I have in my pocket(兜). "
The friend says. "If(如果) I guess right,will you give me one of them?"
The man says,"If you guess right,I'll give you both(两个都) of them. "