Answer:
A hypothesis is an educated guess that is made before research takes place. A theory is an explanation of the natural world and the universe. It explains facts that have already been proven true and is supported by data. A theory can be repeatedly tested and verified, and if proven true, makes the theory even stronger. Even if the theory is proven false, it is simply modified. This is why theories are much more reliable than hypotheses.
A numerical expression includes numbers and operations, so if youre wanting a numerical expression for the number 20, all you have to do is add, subtract, multiply, or divide numbers to equal that.
For example, 5+15=20, 4*5=20, 80/4=20, 29-9=20
The best answer is b - experiment.
An organized process that is used to gather and analyze observations and test a hypothesis is an experiment.
An experiment is the fourth step in scientific method after observation, question and hypothesis.
An experiment is a test that is carried out under controlled conditions with the purpose of demonstrating a known truth, determine the efficacy of a yet untried thing or to examine the validity of a hypothesis.
A hypothesis is a proposed solution for an occurrence that is still unexplained and which does not fit in current accepted scientific theory.