She didn't answer the phone.She ___ be asleep.
| A．couldn't | B．mustn’t | C．might | D．had to |
People should be cautious ______their personal information when surfing the Internet so as to prevent certain computer viruses ______ it.
| A．about; to steal | B．of; stealing | C．with; to steal | D．to; from stealing |
The local police were______ by their authorities to _____ the situation as soon as possible.
| A．said to; control | B．ordered; manage |
| C．instructed; handle | D．told; hold |
Only when people have enough to eat and plenty to wear _______ to talk about environmental protection.
| A．it makes sense | B．does it make sense |
| C．that it makes sense | D．do they make sense |
Through thorough investigation, Dr. John Snow was finally able to prove that the outbreak of Cholera _____ people’s drinking of polluted water.
| A．was close linked with | B．closely linked to |
| C．was close connected with | D．was closely linked with |
By careful observation and precise calculation, Nicolaus Copernicus _____ that there is no one center in the universe and the sun is the center of the solar system.
| A．believed | B．thought | C．concluded | D．imagined |