同样是在同一本书中出现,让我惊讶不已:(1)when was China's first National Day?It was on October 1st,1949.(2)when is your birthday,Ben?It's January 10th.第一句中加了ON,可是在第2句中却没加,是不是哪个错了?还是语法本来就是这样,请会的详细解答!加语法~不会的请不要提意见....很急,这是今晚作业第2个是错的0....