英语翻译There are two kinds of physical activity which require s

英语翻译
There are two kinds of physical activity which require special training.The first demands exact careful movements of the muscles（肌肉）.This kind of activity must be strictly controlled because even a slight movement in the wrong direction will lead a mistake.To type quickly,for example,a person needs training; the slightest movement of a finger in the wrong direction may cause a spelling mistake.A dancer who has to dance on the point of her shoes or turn around on one foot must be trained for a long period of time before she can sense her own center and balance herself.You may have seen a girl walking on a rope across an empty space,which,too,requires a lot of practice.
The second kind of physical activity needs greater strength or extra effort.Most of us get tired if we try to run half a mile without stopping,but a specially-trained person can do this without much effort.Three years ago,some scientists carried out experiments,which produced meaningful and unexpected results.They wanted to find out whether a certain amount of physical exercise would injure those suffering from heart problems.They selected some male patients and trained them in continuous bicycle riding.They were surprised to find that the harmful effect of given amount of physical effort was actually less on the hearts of these trained patients than on those of the patients who were not similarly traineD．This is important because it shows that regular physical exercise enables us to make better use of the oxygen（氧气）we breathe in and that this training,in fact,reduces the amount of work our hearts do.Many tasks which are hard for untrained people are not hard at all for trained people.

有两种需要特殊训练的身体活动.第一种要求肌肉精准细致的运动.这种活动必须被严格控制因为即是在非正确方向的轻微移动也会造成错误.比如为了快速打字,人需要培训,手指在错误方向的最轻微移动会造成拼写的错误.舞者用鞋尖或者单脚旋转的舞姿必须经过长期训练,才能感知自我的重心并保持平衡.或许你见过一个女孩空中走钢丝,同样这也需要大量的练习.
第二种身体活动需要巨大的力量或者额外的努力.我们多数人连续跑半英里便会觉得累,但特殊训练的人可以不费吹灰之力.3年前,一些科学家实施的试验得出了意外的有意义的结果.他们想要查明是否固定量的体能训练对心脏病人有害.他们选取了一些男性病人并且连续训练他们骑单车.他们惊奇地发现接受特定训练的病人所受的消极影响要小于那些没有接受的人.这个发现很重要,因为他表明规律的体能训练能够帮助我们更好利用吸进的氧气,这类训练同时减轻了心脏的负担.很多对于未受训的人是困难的任务,对于受训的人来说已不再困难. 再问： .....求下半段0 0