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. nasa may equip ships with special habitats. spacecraft can use supersonic retropropulsion. problem: spacecraft expose astronauts to dangerous levels of radiation. spacecraft cannot refuel in deep space. large spacecraft are difficult to land safely. solution:

Explanation:

1. For the problem of spacecraft exposing astronauts to dangerous radiation, the text mentions specially - designed habitats and spacesuits as a defense shield, so the solution is "NASA may equip ships with special habitats."
2. Regarding the problem of spacecraft not being able to refuel in deep space, the text states that NASA is working on an electric propulsion system that draws energy from the sun to let ships refuel in deep space, so the solution is "Spacecraft may draw energy from the sun."
3. When it comes to large spacecraft being difficult to land safely, the text says NASA is studying supersonic retropropulsion to help spacecraft land on Mars' surface without crashing, so the solution is "Spacecraft can use supersonic retropropulsion."

Answer:

• Problem: Spacecraft expose astronauts to dangerous levels of radiation. Solution: NASA may equip ships with special habitats.
• Problem: Spacecraft cannot refuel in deep space. Solution: Spacecraft may draw energy from the sun.
• Problem: Large spacecraft are difficult to land safely. Solution: Spacecraft can use supersonic retropropulsion.