I______ thank you too much for all your help to my son while we were away from home.

If the students who killed themselves had only been more confident, their deaths ________.

 ----You needn’t take an umbrella. It isn’t going to rain.----Well, I don’t know. It_____do.

 ---Whose book is this?---It________ be Ning’s because it has her name on it.

_____ people in the world are sending are receiving e-mails every day.