Man has been attracted by outer space for thousand of years.It has been over forty years since man's first landing in the moon. Now,some people belive space exploration is waste of time and money .Theypoint out the fact that it takes billions of dollars carry out space research,but only a few information has been brought back.Therefore the majority of people belive space exploration has been benefited people all over the world.Many new inventions,such as weather satellites,is advances brought about by space exploration.they believe it would bring more advances in the future than we can imaginr at present

thousand（s） of years,
(a)waste of time and money ,
(to) carry out space research(es),
a few a应该去掉，a few 其实表示不少的意思
has been benefited been 去掉
Therefore--but,
is --are
would--will