Lingling says Miss Yu has gone to Shanghai, _____ that be true?—It _____ be true because I saw her in the office just now.

We are so sorry to hear a big earthquake hit the northwest of Sichuan _____May 12. [ ]

Don’t be late _______ class again, OK? —Sorry, I won’t. [ ]

My son seldom has _______ breakfast.—It is _______ unhealthy lifestyle. You must ask him to change it.

I lost a set __________ keys.[ ]