Make sure that your computer room is 100% ________ of insects because they can really cause trouble to your machine.
| A．absent | B．rare | C．free | D．short |
.
The river _______ in the late summer, so we could go across it easily.
| A．dried out | B．dried up | C．dried off | D．dried down |
.
Who is the person ____is talking about the accident ___happened on Highway 104?
| A．which, which | B．who, what | C．that, that | D．what, what |
.
---Goodbye, Peter, remember me to your parents.
---_______.
| A．It’s very kind of you to say so. | B．Thanks, I will. |
| C．You are so kind. | D．Thanks, what a good idea. |
.
_________ 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 |