It is dependant on the context within which you wish to use the phrase. C and B are both correct. B would most probably be used as a phrase on a signboard informing passengers that a flight has been cancelled. C is more suited to enquiries that are received telephonically.
The phrase "had already left" is grammatically correct. The phrase "had already been gone" is not grammatically correct.
No, the sentence is not grammatically correct. It should be: "It had been a long time since I had written to you."
grammatically speaking no. it would be: Have you been there already?
sorry i have been reading at about. What does it mean and is grammatically correct?
"You could not have been" is grammatically correct. "You could not have been at the cinema last night, because I saw you in the park."
Yes, very correct.
both the sentence are correct
These groups have been disqualified......
No. "Him and I have been together." is not correct. The word him is an object pronoun, not a subject pronoun. The proper form of the sentence is "He and I have been together."
Yes, that is grammatically correct.
"You have always been the best" would be more grammatically correct.
No. It's only grammatically correct if one says "has been"