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 Alzheimer's and Parkinson's Disease can be prevented.

人们对克隆的一些伟大希望包括在需要进行移植手术时人们能使用克隆器官。例如：肺癌患者可能仅需换个健康的肺。科学家也期待着有一天长期坐轮椅的人能再站起来，老年痴呆症及帕金森氏症等疾病也都能事先预防。

重点解析：

clone vt. 克隆，复制
You wonder why they can clone sheep but you can't dupe the cows.
你不明白为什么他们能克隆羊而你不能复制牛。
transplant vt. 移植
It is now possible to transplant organs from animals into people.
现在将动物身上的器官移植入人体内已经成为了可能。
The doctors will transplant a human heart into the patient.
医生们将把一颗人的心脏移植到这个病人身上。
organ n. 器官
Alzheimer's n. 阿尔茨海默病（老年痴呆症）
Parkinson's n. 帕金森氏综合症
prevent vt. 预防，防止
Scientists are trying to find ways to prevent disease.
科学家们正试图找到预防疾病的方法。