—Who is the girl standing over there? —Well, if you _____ know, her name is Kate.

–What do you think we can do for our parents? --You ____ do anything except to show your love -- a kind word, a warm smile and a helping hand.

Being constantly exposed to advertisements is annoying, but it ______ be pleasant sometimes.

Bring a map of China because you _______ want to travel around.

— Do you know where Miss Gao is? I couldn’t find her anywhere.— She ________ have gone far, for her coat is still here.