—      I borrow your camera? I want to take some photos. —Sure, here you are.

I am fond of my sister but she has one serious shortcoming. She _________ be really stubborn.

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

—Must I clean the blackboard now?    —No, you _______ clean it later.

—Where _____ Mary have put the empty bottles? — She _____ them away. They must be somewhere.