No ready technical data was ______ ，but we managed to go without that.
| A．believable | B．convenient |
| C．available | D．accessible |
.
_________ it was to become was a mystery until the dust began to slowly combine into a ball moving around the sun.
| A．That | B．What | C．Which | D．Whether |
.
I'm amazed that Mr Harris _________ have said nothing about the matter.
| A．can | B．should | C．would | D．must |
.
— I will take my mid-term exam tomorrow.
—_________.
| A．Forget it | B．Congratulations | C．That’s all right | D．Good luck |
.
Look at the sign, Sir. We don’t permit _________ in the hall.
| A．smoke | B．to smoke | C．smoking | D．to have a smoke |
.
— Do you know why the teacher asks for me?
— He wants you to _________ your absence(缺席) last night.
| A．account for | B．call for | C．reach for | D．send for |