Lin Tao goes to the country to see his grandparents ---(two)

填写twice.是two的序数词形式
Lin Tao goes to the country to see his grandparents twice a month.林涛每月去乡下看两次他奶奶.
序数词是几次,其中一次once,两次twice,三以上就数字+times,例如five times