Complete the sentences with the correct form the words and phrases in the box.
borrow discover life model recently space station space shuttle
1.Astronauts take the _____to get to the_____
2.they have not___ any_____on mars yet
3.the____of the space station isn't Daming's,and he only wants to___it
4.astronauts haven't been to the moon____.the last time was over 30 years ago