The computer system _____suddenly while Paul was searching for information on the Internet.
| A．broke in | B．broke out | C．broke up | D．broke down |
-Why didn’t you go to the dance last night?
--If I tired, I would have.
| A．were not | B．hadn’t |
| C．haven’t been | D．hadn’t been |
My mom sang this song to me when I was 5 years old. It ______in my heart ever since.
| A．had remained | B．is remained |
| C．has remained | D．has been remained |
She _____ the book sometime in the past as there is no way she could have answered the questions so accurately.
| A．ought to read | B．must have read |
| C．must read | D．should have read |
—Can I buy a Friday’s air ticket for Washington?
—I hate to say this, but there are no tickets ______ for Friday’s flight.
| A．precious | B．vacant |
| C．available | D．accessible |
Marie witnessed everything but it is amazing that she______ have said nothing about the murder.
| A．should | B．may | C．must | D．can |