今天下午可能会下雨。如果是这样的话，我们将不得不在室内举办派对。

It might rain this afternoon. ___If ___so, we'll have to have the party indoors.

你会准时吃晚饭吗？如果是这样的话，我会做你最喜欢的菜。

Will you be in time for dinner? ___If ___so, I'll cook your favourite dish.

你计划参加会议吗？如果是这样的话，请确认你的出席。

Are you planning to attend the meeting? ___If ___so, please confirm your attendance.