======================语法常识回顾=================
这里讲述的是将来完成进行式及其相应的时间状语。
Will have been doing 将一直进行了···有多少时间
例如：
1)· I shall have finished this novel in two months time. 二个月之后我就把这本小说写成了。
· 比较： I shall have finished this novel by December. 到十二月之前我就把这本小说写成了。
2)·I shall have been writing this novel for ten years by then (by next July).到那时之前（到明年七月之前）我将一直写这本小说有十年之久了。
《 Dangerous Descent / 危险的出舱活动》


In future, astronauts will be required to descend from a spaceship while it is still in space and to return to it. The ability to do this will be necessary in future flights to distant planets. Scientists are now trying to discover if this is possible.
{ 到将来，人们将要求宇航员在飞船停在太空时从飞船里走下来并且再回到里面去。再将来向遥远地行星飞行时就需要有这样做的能力。科学家们目前正在试图发现有没有这种可能性。}
The spaceship Astra which left the earth a short time ago, will be travelling three hundred miles into space. At a certain point, the Astra will stop for a short time and an astronaut will attempt to leave the stationary spaceship and then return to it.
{不久前离开地球地阿斯屈拉号飞船准备飞行三百英里进入太空。阿斯屈拉号将在某一地点稍停片刻，而宇航员将试图离开静止的宇宙飞船然后再回到里面去。}
We shall not know whether the experiment has been successful until we have received a radio message. The first message is expected to arrive at 7 o'clock this evening. By that time, the Astra will have been flying through space for seventeen hours and will have circled the earth a great many times. When the first radio message have been received, the results of the trip will be announced immediately.
{直到我们接受到了无线电信息时才会知道实验是否已成功。第一次信息预计在今晚七点到达。到七点钟之前一段时间，阿斯屈拉号将一直穿越太空飞行了有十七个小时，同时也将环绕地球转过好多圈了。一 第一次电报收到时就将立即宣布这次飞行的结果。}


词 汇 注 解


ability 能力，用 to + 不定式
will be travelling 准备（打算）飞行
attempt to 试图
stationary 静止不动的，stationery:文具，信笺
a radio message 无线电信息
be expected to 预计···
a great many times 许多许多次
descent 下降