---Must Jack come to sign his name on the paper?---Yes, he_____ .

---Must he remember everything he has learned in the class?---No, he _____.

 --- Do we have to hand in our research reports this afternoon, Professor Smith?--- Yes, you _______ . I will be waiting to check them all the afternoon.

The World Wide Web is sometimes jokingly called the World Wide Wait because it ______ be very slow.

The bus ____ at six, but it arrived an hour later.