It _________ be the only way to solve the problem. There are other choices.
may not
mustn’t
need
should
---Whose is ______red ball over there? ---It’s Cindy’s. She has ______red ball like this.
—We’re going to have a basketball match with Class1. —________!
—Please open the window, Daniel. —________? I can’t hear you well.
—Which man is your Maths teacher? —________.
—Excuse me, what day is it today? —________.