Mr White usually visits China in February and August every year.
怀特先生通常每年二月份和八月份来中国、那个·题是Mr White usually comes to China ___ ___ ___Mr White usually comes to China （twice）（a）（year）一年两次。或者Mr White usually comes to China （for）（two）（months）两个月。个人倾向第一种