25. ---- Why didn’t you pick up the MP4?
---- I ______ it, but I didn’t carry that much money.

----- Is that Mr．Smith over there?
----- No, it _____ be him --- I am sure he is much taller.

---Is it good to look up every new word when I come across it in reading?
---No. You ______because you are likely to guess the meaning from the context.
A. can’t            B. mustn’t         C. don’t have to       C. ought not to

3．--- Will Helen get disappointed if I tell her she failed?
--- I think she__________.

12. But for your help, I_____________the exam.

-- _____ you make so much noise, Mary? Your father is sleeping now.    
--Sorry, Mum. I’ll take care not to.

We were all waiting for you. You _____ for the seaside by yourself without
leaving a message.

–There were already five people in the car but they managed to take me as well.
--It _____ a comfortable journey.

–Why, I couldn’t get you on the phone this morning.
--We _____ tennis in the yard when you called.

24. — Someone is knocking at the door. It _________ be Tom.
— No, it ________ be him; he has gone to Sydney.