1.It's Saturday tomorrow.Parents (will have) a birthday party for Maria.
(明天是将来 ,用将来时)
2.Look at the clouds.it （is raining）(正在下雨,用现在进行时)
3.there (will be)a sports meeting next month.(将来时)
4.I (shall send)an e-mail to my friend this evening.(将来时,也可用 am going to send )