Im chemistry we are solving chemical reactions and on the assignments our teacher put the questions as riddels and i can not get this one: what can you "throw" and not "catch"? what is the answer?

Which of these statements best explains why space exploration should be encouraged? it prepares humans to live without oxygen. it dispel myths about objects in space. it prevents comets and asteroids from striking earth. it creates technology to absorb harmful radiations in space.