The last one, the planets formed at the same distance from the sun.
Answer:
D
Explanation:
Zebra mussels can be a nuisance in novel ecosystems. When introduced in a non-native ecosystem with no natural predators, they reproduce rapidly displacing native mussels. Zebra mussels take up much of the algar that feeds the other native species hence starving them to death and causing their numbers to plummet. In addition, they attach to the other mussels and clog up power plants, that use the local water, water intakes.
A theory is a hypothesis that someone had but has not proven it.
A law is something that is proved.
Example: Sir Issac Newton had a theory on gravity he sat under a tree and then had a conclusion.