论文部分内容阅读
Suppose that we were space travellers,visiting the earthfrom some distant planet. It would be difficult to detects muchtrace of the atmosphere until we were in the region of the low-er part of the orbit of the first sputnik,say between 200 and
Suppose that we were space travellers, visiting the earthfrom some distant planet. It would be difficult to detect muchtrace of the atmosphere until we were in the region of the low-er part of the orbit of the first sputnik,say between 200 and