Scientists and doctors across the world have done _____ research over the years, hoping to find a cure for cancer.
| A．a great deal of | B．quantity of |
| C．quite a few | D．a large number of |
Thepowerstationwasbuiltontheriverwithourvillageandsomeothers___withelectricity.
| A．tosupply | B．supplied | C．supplying | D．havingsupplied |
Allhiswork___,helefthisofficeatease.
| A．finished | B．hadbeenfinished | C．finishing | D．tofinish |
Everything___intoconsideration,hisworkiswelldone.
| A．taking | B．taken | C．hasbeentaken | D．beingtaken |
Itisabeautifulvillagewithamountain____it.
| A．Surrounded | B．surrounding | C．havingsurrounded | D．havingbeensurrounded |
Thelastplane___,theyhadtostayinthehotelforanothernight.
| A．left | B．havingleft | C．havingbeenleft | D．beleaving |