美国英语听力80篇4 Lesson64
时间：2018-12-26 作者：英语课 分类：美国英语听力80篇
[00:07.52] You probably know a famous saying about the importance of eating apples
[00:14.58]It is,"An apple a day keeps the doctor away."
[00:19.83]Now,a new American study shows eating apples may help fight cancer,too.
[00:28.16]Research scientists at Cornell University in Ithaca,New York
[00:34.93]say a combination of chemicals found in apples is important for good health.
[00:42.58]The study shows that the combination of chemicals play an important part
[00:49.74]in anti-cancer and anti-oxidant activity.
[00:55.17]An anti-oxidant is one of many chemicals that reduce or prevent oxidation
[01:04.13]This prevents damage to cells and tissues caused by atoms
[01:10.90]or molecules 1 in the body called free radicals 2.
[01:16.25]The scientists say the chemicals are in both the skin and the flesh of apples
[01:24.69]Results of the study were reported in the publication Nature.
[01:30.72]The New York Apple Research Development Program
[01:35.87]and New York Apple Association paid for the study.
[01:41.51]The Cornell researchers studied the chemicals,or extracts,
[01:48.04]taken from the skin and flesh of red apples graown in New York State.
[01:55.59]They studied the effectiveness of the apple extract in fighting cancer
[02:02.23]and preventing cell damage.
[02:05.78]The researchers treated colon 3 cancer cells
[02:11.21]with fifty milligrams of apple extract.
[02:16.46]Extracts from the apple skin reduced the growth of cancer cells by 43%.
[02:25.48]Extracts from the fruit's flesh reduced the growth of cancer cells by 29%.
[02:34.62]The researchers also treated human liver cancer cells with apple extract.
[02:42.74]Extracts from the apple skin reduced the growth of those cells by 57%.
[02:51.99]Extract from the fleshy part of the apple reduced the cancer cells by 40%.
[03:00.32]Lead researcher Rui Hai Liu said scientists have known
[03:07.38]that apples are good for human health.
[03:11.90]Mister Liu says some scientists are interested in testing single vitamins
[03:19.34]or other substances to see if they alone fight disease.
[03:26.16]He says his study shows no single substance works alone to reduce cancer
[03:34.20]Instead,he says the combination of chemicals in apples is effective.
[03:41.65]Mister Liu says eating fruits and vegetables is better
[03:47.68]than taking extra vitamin pills.
[03:51.42]He says people can get enough anti-oxidants from food
[03:56.67]without worrying about any possible harmful effects.
- The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
- Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。