Saving lives has always been an important mission of science. Now science， and indeed all society， is facing a new dilemma： whether or not to try and save more lives through human cloning.

The first cloning experiments in the 1950s involved frogs and toads. It was not until 1997 that scientists successfully cloned the first mammal， the now world-famous sheep known as Dolly. Cloning techniques have continued to improve since then， and today there are cloned mice， salmon， and cattle.

Some scientists want to apply the methods used in cloning animals to produce skin， organs， and other body parts for humans. One of these methods involves taking adult cells from the brain or blood and growing them into new tissues. Another， more complex， technique takes embryo cells and develops them into a wide variety of cell types and tissues. It is this planned use of human embryos that has resulted in controversy and criticism.

The cloning of human cells provides the potential to find cures and eliminate diseases. The dream of some researchers is to create a utopian world of good health. Others question whether it is right to “Play God” in an attempt to cure the disabilities and diseases.

Some of the great hopes for cloning include the ability to perform transplants， whenever they are needed， using cloned organs. For example， people with lung cancer may simply have their lungs replaced with healthy ones. Scientists also look forward to the day when people in wheelchairs can walk again， and illnesses such as Alzheimers disease and Parkinsons disease can be prevented.

Many people fear the effects cloning could have on our society. They imagine masses of identical people， and the production of “perfect” humans for warfare or slave labor. We might even see headless human bodies being stored at hospitals for their “spare parts”. With such possibilities for the 21st century， human cloning will no doubt continue to receive widespread attention and scrutiny.

挽救生命一直是科學(xué)研究的一項重要使命。如今，科學(xué)研究，其實是整個社會，正面臨著一個新的困境：是否要通過克隆人類來挽救更多的生命。

克隆實驗開始于20世紀(jì)50年代，對象是青蛙和蟾蜍。直到1997年，科學(xué)家才成功地克隆出了第一例哺乳類動物，即舉世聞名的“多莉羊”?？寺〖夹g(shù)從那時起得到了持續(xù)的提升，現(xiàn)在已經(jīng)有克隆老鼠、克隆鮭魚和克隆牛。

一些科學(xué)家想用克隆動物的方法來制造出供人類使用的皮膚、器官與其他的身體部件。方法之一是從大腦或血液中提取成熟的細(xì)胞，把它們培養(yǎng)成新的組織。另外一種較為復(fù)雜的技術(shù)，則是把胚胎細(xì)胞培養(yǎng)成各式各樣的細(xì)胞種類及組織。正是這個計劃使用人類胚胎的想法引發(fā)輿論爭議與批評聲浪。

克隆人類細(xì)胞為找到治愈疾病的療法并消滅疾病提供了可能性。一些研究人員的夢想是建立一個沒有疾病的烏托邦世界。其他研究人員則質(zhì)疑人類企圖治愈傷殘者和治療疾病去扮演上帝的角色是否正確。

人們對克隆的一些殷切希望包括在需要進(jìn)行移植手術(shù)時，人們能使用克隆器官，比如肺癌患者可能僅需換個健康的肺?？茖W(xué)家也期待著有一天坐輪椅的人能再站起來，老年癡呆癥及帕金森綜合征等疾病能得到預(yù)防。

很多人擔(dān)心克隆會對社會產(chǎn)生影響。他們想象有一天可能會出現(xiàn)一大群長得一模一樣的人和應(yīng)戰(zhàn)爭或苦役需要而制造出的“完美”人類，我們甚至可能看到存放在醫(yī)院里作備用的無頭的人體。在21世紀(jì)具有多種可能性的情況下，克隆人類毫無疑問會繼續(xù)受到廣泛的關(guān)注及審視。

dilemma /d?'lem?/ n. （進(jìn)退兩難的）困境

eliminate /?'l?m?ne?t/ v. 消除

Fatty foods should be eliminated from the diet.

transplant /'tr?nsplɑ?nt； 'tr?nspl?nt/ n. （器官）移植

He was recovering from a heart transplant operation.

scrutiny /'skru?t?ni/ n. 仔細(xì)的審視

Their activities have come under police scrutiny.