Samples of blood from Cholera infected patients have been sent to the blood center _______.

It has been announced by our provincial government that another two medical teams will be sent to ______ the injured people in the severe earthquake.

 ______ the aids from the outside, the positive attitude of the disaster-stricken people _____ the key role in the reconstruction of their destroyed towns and villages.

 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.

Through thorough investigation, Dr. John Snow was finally able to prove that the outbreak of Cholera _____ people’s drinking of polluted water.

 Only when people have enough to eat and plenty to wear _______ to talk about environmental protection.

The local police were______ by their authorities to _____ the situation as soon as possible.

 People should be cautious ______their personal information when surfing the Internet so as to prevent certain computer viruses ______ it.

 We the Chinese are not to be ______, ________the situation is.

Nicolaus Copernicus’ discovery about the universe is ______, which ______later achievements in astronomy science.