-- Is this a pen? -- Yes , ________ is.A. this B. that C. it
“When did you ________, David?” “Ten minutes ago.”
Of all the subjects, art is ________.
_____ poor I am ! I ‘m going to find some part-time jobs.
Tom ______ be in his office so late that night. I saw him with his friends in the restaurant .
---How many children have you got ? ---Two , _______ of them are studying in the university.