Space travel has been possible for some time and some people think the space tourism could be developed in the future.Do you think it is a positive or negative development?

太空旅行让人体处在极端的环境中，这对人的身体和心理健康都有可能造成伤害。本期 “随身英语” 介绍宇航员在太空中可能遇到的健康问题，并讨论关注宇航员的健康对航空事业和医疗科学发展的意义。 Astronaut Frank Rubiales has returned to Earth after 371 days in space ...