Question

read the text,
to the naked eye, mars seems as distant as the stars. but humans may set foot on the red planet in the near future, according to scientists at the national aeronautics and space administration (nasa). to make it happen, nasa is pursuing creative solutions to the problems posed by deep space. specially designed habitats and spacesuits may offer a defensive shield to protect astronauts from extended exposure to radiation. nasa is also working on an electric propulsion system that draws energy from the sun. this system would let ships refuel in deep space, without space stations nearby. most ambitious of all, nasa is studying supersonic retropropulsion, a process that fires engines during landing, to help spacecraft land on marss surface without crashing.
match the problems with their solutions.
spacecraft may draw energy from the sun.
spacecraft can use supersonic retropropulsion.
nasa may equip ships with special habitats.
problem
spacecraft expose astronauts to dangerous levels of radiation.
spacecraft cannot refuel in deep space.
large spacecraft are difficult to land safely.
solution

Explanation:

• For the problem "Spacecraft expose astronauts to dangerous levels of radiation", the text mentions "specially designed habitats... offer a defensive shield to protect astronauts from extended exposure to radiation", so the solution is "NASA may equip ships with special habitats".
• For the problem "Spacecraft cannot refuel in deep space", it says "NASA is also working on an electric propulsion system that draws energy from the sun. This system would let ships refuel in deep space", so the solution is "Spacecraft may draw energy from the sun".
• For the problem "Large spacecraft are difficult to land safely", the text states "NASA is studying supersonic retropropulsion... to help spacecraft land on Mars's surface without crashing", so the solution is "Spacecraft can use supersonic retropropulsion".

Answer:

1. NASA may equip ships with special habitats.
2. Spacecraft may draw energy from the sun.
3. Spacecraft can use supersonic retropropulsion.