[ Grammar ]
Once ____ for viruses, the software can be installed in the school computer system for use.
A. has tested
B. tested
C. testing
D. is tested

Random Topics:
Time PhrasesInfinitives for reasonsObject PronounsTag QuestionPrepositionsConnectivesHave GotPhrases and TensesPassive Voice and ModalsSimple Past TensesOther quiz:
Grammar › ViewIdentify the participial phrase in the following sentence: “The cat, sitting by the window, watched the birds.”
A. The cat
B. sitting by the window
C. watched the birds
D. by the window
Tenses › View
Choose the correct sentence:
A. They are go to the market.
B. They going to the market.
C. They were going to the market.
D. They go to the market.