Question

Since the beginning of history, man has been attracted by the idea of living forever, of wining the fight against death and disease. So far, this has only remained a dream, though a very powerful one. Many people have wondered whether it would be possible to find a way to preserve(保存) human bodies, and what would be the best way to preserve human bodies.

It has long been known that meat or fruit can be kept fresh for long periods by freezing; in ancient China, for example, food was stored with ice to keep it fresh. This method could also be useful for preserving humans, and in fact many people have explored this possibility.

However, most living beings that exist under warm conditions die when frozen. This is because of the harmful effects of freezing ice crystals（晶體）, which form sharp cutting shapes that harm the cells.

In the 1940s, Dr B．J. Luyet and a group of scientists in England were working on the problem of freezing cells without damaging them. Since the harm caused by ice crystals was the main cause of the damage, Luyet suggested removing some or all of the water from the cells before freezing them.

Using living cells from chicken, Luyet and his assistants discovered that they could partly dry the chicken cells, using a mixture of the white part of an egg and glycerin(甘油). Some success was achieved．The chicken cells were dried, frozen for a period of time, and then carefully unfrozen. Almost all the cells recovered when they reached normal temperatures.

Since then, the cooling of whole animals to a temperature very much below freezing point for later unfreezing has become more of a possibility, and the glycerin method would probably be used to do this. When this can be done completely and successfully, science will have moved much closer to its aim of freezing and storing incurable patients until the day they can be cured.

56．The passage is mainly about ___________.

      A．the possibility of preserving human bodies by freezing

      B．the practice of preserving food by freezing

      C．the harmful effects of freezing

      D．how to remove water from living cells

57．The idea of freezing human bodies to preserve them ___________.

      A．comes from that of keeping meat and fruit fresh by freezing

      B．was invented in ancient China

      C．could hardly be realized by people

      D．is widely accepted by the scientific world

58．According to the passage, freezing is___________.

      A．the best way of preserving food

      B．a way of removing water from living cells

      C．a way of realizing the idea of preserving human bodies

      D．harmful to living cells and cannot be used to preserve them

59．Glycerin can be used ___________.

      A．to freeze only chicken’s living cells

      B．to unfreeze living cells

      C．to remove water from living cells

      D．to change the shapes of crystals

60．The success achieved by Dr Luyet and his helpers was a long step towards ___________.

      A．keeping meat or fruit fresh

      B．living forever

      C．changing the shapes of ice crystals

      D．preserving human bodies for long periods

Answer 1

AACCD