Pollination twice a year一年异地两次授粉
Inspection twice a year一年两次的工厂审查
Happening twice a year一年两次的
fertilizing twice a year全年两回施肥法
I go twice a year我一年去两次
Once and twice a year一年一两次
twice-a-year一年两次的
once or twice a year一年一次或两次
visit them twice a year一年看望他们两次