Complete the text by using suitable forms of the words. Write them down.
Future astronauts on Mars
Since the 1960s, Mars missions ____ an important part in NASA’s space programs.
What would NASA scientists do if they ____ to build a Mars base? Like any human ____, it would be best located near accessible water. Water would be essential for everything from producing ____ goods to producing the rocket fuel ____ would be needed in order to return to Earth. However, by ____ all that water to Mars, missions would become enormously costly and risky.
In 2015, NASA ____ to try to find water sources on Mars that could be easily reached.
Although scientists already have a profound ____ about the Red Planet, further efforts will be needed before human missions to Mars might be possible at all.
Adapted from: https://mars.nasa.gov/news/8851/where-should-future-astronauts-land-on-mars-follow-the-water/ (22. 07. 2021)
Choose the suitable forms of the words from the list below (a–h):
a) to play
b) to want
c) settle
d) agriculture
e) ?
f) to transport
g) to begin
h) to know
