4. This metal (X) displaces copper from copper sulphate solution but does not
displace zinc from zinc sulphate. From this we can tell that the order of reactivity
(most reactive first) is
a. zinc; copper; X
b. zinc; X ; copper
c. copper ; X ; zinc
d. X; zinc; copper;

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.