It __be the vocabulary that caused you the problem in the exercise because you know a lot of words.

－These peaches really juicy.－They ____ be! Just see the price, $3,99 a pound. Very expensive, aren’t they!

 “ Even if Sun Yang failed to kill passers-by in his car, he ___ be fined and put into prison for 2  weeks according to the law.” the judge said.

—Must I finish the paper tonight?    —No, you _______ finish it tomorrow.

I was really busy these days, otherwise I _______ to your birthday party last night.