Vitamin D helps our bodies make a special chemical,and this special chemical, ____ , affects our brains,making us feel happy.
— I don’t think he is studying English in his room now. — Oh! ________?
-It was careless of you to leave out some important information. -Oh, my god! _______.
Tom doesn’t want to take part in any school activities,________.
—Will he be back by ten tonight? —No, _____.
—Tom, would you like to come to our dinner party? — _____.