北半球副热带高压的年变化规律为（）。
A．冬强夏弱、冬南夏北
B．冬强夏弱、冬北夏南
C．冬弱夏强、冬北夏南
D．冬弱夏强、冬南夏北
参考答案：D
Whenever a natural disaster happens, we should offer ____ help we could to those victims.
A．however
B．whatever
C．whenever
D．whichever
