I took mathematics and physics because I think that ________ very important for me to make further research in this field.
| A．what is | B．they are | C．this | D．which are |
.
Most business letters and government reports are the main situations _________ formal language is used. ^*
| A．where | B．that | C．what | D．which |
.
. I heard she _________ a book last year, but I don’t know if she has finished it.
| A．was writing | B．wrote | C．had written | D．writes |
.
. Few visitors leave Rio feeling _________.
| A．disappointing | B．to disppoint | C．disappointed | D．being disppointed |
.
He made a big mistake, and _________, he lost his job.
| A．as a result | B．as soon as | C．in case | D．even if |
.
The forest guards often find campfires that have not been _________ completely.
| A．put away | B．put out | C．put up | D．put off |