虽然人类早已实现了在月球上的行走，虽然我们已经有能力去探寻太阳系以外的世界，虽然航天技术正在飞速地发展，但还是不可避免地会有各种意外发生，致使许多优秀的科学家离我们远去。
Hints:
eliminate 减少
experimental
programme(后面出现这个词也请以这种写法为准）
precaution
Apollo 阿波罗
engine-chamber
nitrogen gas
collapse
grief
每段开头请换行并空两格
Although it is impossible to eliminate all risks from such a complex and experimental project as the American space programme, every precaution is taken to reduce the possibility of injury. Nevertheless, accidents do happen. The first major casualties occurred when, despite every precaution, fire broke out on the Apollo five capsule on January 27th, 1967. In spite of every effort to save them, three men died in this terrible accident. The programme continued without pause, however, and there were no more serious injuries until 1981. Then, the engines having been successfully tested on an earlier occasion, a rehearsal for the actual launching was held. Not knowing that an engine-chamber was full of nitrogen gas, used to clean the motor, six technicians entered for routine work after the final rehearsal had been declared successful. They collapsed as soon as the gas entered their lungs. One man died and the others were very ill. Though everyone involved was shocked and grieved by this apparently unnecessary accident, preparations continued for the actual launching later that year. However hard we try, accidents are bound to happen whenever a new and challenging project is undertaken. It seems to be the price of progress.