(假如)没有生病和衰老，唯一能杀死人类的就可能是事故、自杀或者谋杀。如此，我们的平均寿命就可能超过1200年。

Sentence No.1 Like food and shelter, clothing is a basic human need. One reason people began wearing clothing was for protection. Rough garments protected them from animal bites, scratches, and burns. Clothing also kept the people warm and dry.
Sentence No. 2 The professor said his best teaching years were between 35 and 50 because he was more open to new ideas. As he grew old, he became more mature, more responsible and sensitive to the world around him.
Sentence No. 3 Without disease or the aging process, the only things to kill humans would be accidents, suicides, and murder. If that were the case, our average lifespan would probably be 1200 years or more.
Sentence No. 4 American community colleges provide general education courses for all post secondary students. According to statistics, this year over 12 million students were enrolled in community colleges, amounting to more than half of all undergraduate students in the US.
Sentence No. 5 The prospect of a hung parliament saw the value of sterling slide against the dollar. By Friday, sterling was down 1.7% against the dollar at $1.2735. The weakening pound makes imported goods’ prices higher and reduces domestic demand.