The computer center, ________ last year, is very popular among the students in this school.
| A．open | B．opening | C．have opened | D．opened |
Theyfirstreachanagreementonthebasicprinciple,thedetails____later
| A．toworkitout | B．havingbeenworkedout |
| C．tobeworkedout | D．beingworkedout |
Christmas____,thefamilywasfullofexcitement.
| A．wasthenonlydaysaway | B．werethenonlydaysaway |
| C．thenonlydaysaway | D．havingbeenthenonlydaysaway |
____fiveminutes____beforethelasttrainleft,wearrivedatthestation.
| A．Therebeing;togo | B．Itwas;left |
| C．Ithad;left | D．Therewas;togo |
Thepowerstationwasbuiltontheriverwithourvillageandsomeothers___withelectricity.
| A．tosupply | B．supplied | C．supplying | D．havingsupplied |
Allhiswork___,helefthisofficeatease.
| A．finished | B．hadbeenfinished | C．finishing | D．tofinish |