— A well-balanced diet together with regular exercise ______ you'll make it.
A:so
B:and
C:but
D:or
农作物
水稻
茶树
玉米
马铃薯
pH
6.0~7.0
6.9~7.0
7.8~8.1
4.8~5.5
试作出漂浮在水面上的足球所受重力的示意图.