Do you want to live another 100 years or more? Some experts say that scientific advances will one day enable humans to last tens of years beyond what is now seen as the natural limit of the human life span.

    “I think we are knocking at the door of immortality(永生),” said Michael Zeya, a Montclair State University business professor and author of two books on the future. “I think by 2075 we will see it and that's a conservative estimate(保守的估计).”

    At the conference in San Francisco, Donald Luria, a professor at New Jersey Medical School in Newark said advances in using genes as well as nanotechnology(纳米技术) make it likely that humans will live in the future beyond what has been possible in the past. “There is a great push so that people can live from 120 to 180 years,” he said. “Some have suggested that there is no limit and that people could live to 200 or 300 or 500 years.”

    However, many scientists who study in ageing are doubtful about it and say the human body is just not designed to last past about 120 years. Even with healthier lifestyles and less disease, they say failure of the brain and organs will finally lead all humans to death.

    Scientists also differ on what kind of life the super aged might live. “It remains to be seen if you pass 120, you know; could you be healthy enough to have good quality of life?” said Leonard Pooh, director of the University of Georgia Gerontology Centre. “At present people who could get to that point are not in good health at all.”

    Can plants eat people? Probably not, but there are many plants that eat meat. Some of them are big. And they can eat small animals. One famous meat-eating plant is the Venus flytrap(蝇草).

    The Venus flytrap is a very strange plant. It grows in dry parts of the United States. Its leaves are like the pages of a book. They can open and close very quickly. Inside the leaves, there are three small hairs. If a fly (苍蝇) touches one of the hairs, the leaf closes quickly. The fly cannot get out. In about half an hour, the leaf presses the fly until it is dead. Then, the plant covers the fly. Slowly, the plant eats the fly.

    Why do plants do it? Most plants get what they need from the sun, the air, and the ground. In some places, the ground is very poor. It doesn't have all these important things, especially nitrogen(氮).Animal meat has a lot of nitrogen, so some plants eat meat to get what they need. Let's hope that some of the bigger plants don't get the same idea!