When the traveler felt tired, he stopped ___.
Penicillin became the greatest drug of the 20th century, without ______ many people ______ from sickness or even small wounds.
Hot water is converted to electricity by a turbine. The underlined word can be replaced by ______.A. conveyed B controlled. C. chosen D. Changed
The noise coming from upstairs are driving me mad.
We should take effective measures to the infectious disease.
Since Tom downloaded a virus into his computer, he cannot open the file now.