One of the difficulties we have English is how to remember new words and expressions.

There is ______ “u” in the word “your”.

You speak English so well. ______ have you learned English? –For 5 years.

Look! The light is still on. Is Mr Wu working in his office？—No, it _____ be Mr Wu. He has gone to Nanjing for a meeting.

______ does this scarf belong to?— Let me see. Oh, it may be ______.