What do you think of the most important inventions in the world? The TV? The printing? The telephone? Or the computer? A report shows that they are not the only important inventions．

Here are ___1___ other important inventions．One of the simplest inventions is the toilet（厕所）．Before toilets，waste ran into rivers from ___2___ houses．Illnesses were common in big cities，and it was often difficult to find clean drinking water．

Animal food is another important invention．___3___ the invention，most animals were killed every autumn because there was not enough food for them in winter．After hay（干草）became a kind of common animal food，animals ___4___ live through the long winter．

The third great invention is glasses（眼镜）．Glasses make people read，write and do “close work” easily after the age of 45．___5___ glasses，the world would be difficult for the people above 45．

1．A．two                       B．three                    C．four

2．A．people                   B．the people's          C．people's

3．A．Before                   B．After                   C．During

4．A．can't                     B．could                   C．couldn't

5．A．For                       B．With                    C．Without