When a spacecraft travels, one of the major problems is reentry into the Earth ’s _______.
A、surfaceB
暂无解析
He always has a lot of _______ ideas in his mind , and sometimes we do not even know what he is thinding about.
Withthehelpofthegovernment,alargenumberofpeople---_______afterthefloodin1991.
It is not ---_______ for me to return all the books to the library now because I still need some of them for my research.
Please be serious. I am not _______. You should consider it carefully
This river is so big that it is impossible to build a _______under it without modern technology.
