为你解答。如果明天下雨,我将不得不待在家里。If it rains tomorrow, I will have to stay at home.解释：if从句用一般现在时表示将来。
lfitrainstomorrow，IwiIlhavetostayathome．无所不览是100%正确的!
If it doesn't rain tomorrow, I will have to stay at home
