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

The public transportation is very convenient in that big city, so there ________ be any difficulty in traveling around.

—Where is Sally?—I’m not sure. She      in the library.

— _    good time we had at the party last night!— Yes. It was _____ exciting party that I would never forget it.

The teacher told us the best way _____ English.