The program is like a window on the world ____ you sit by it and fix your attention on what it shows.
| A．if | B．as | C．while | D．unless |
Why don’t you bring ______ to his attention that you are too ill to go on working?
| A．them | B．that | C．this | D．it |
______ as planned, our work was highly thought of.
| A．Completed | B．Completing |
| C．Having completed | D．To be completed |
In the past few years, sea ice ____ in the Arctic as a result of global warming.
| A．had melted | B．has been melting | C．melted | D．is melting |
Peter told us the work would be finished by next month, _____ personally I doubt very much.
| A．that | B．when | C．which | D．it |
By the time our teacher arrives tomorrow, all the work _____,with which he will be content.
| A．is accomplished | B．will have been accomplished |
| C．will be accomplished | D．has been accomplished |