The words that complete the blanks are hypothesis and experimentation.
<h3>What is scientific knowledge?</h3>
The process by which scientists obtain information and establish knowledge is;
Observation ---> hypothesis ------> experiments ------> Theory -------> Law.
Thus after the process of observation what we have is merely a scientific hypothesis that needs to pass through the process of rigorous experimentation before it is proven to be true.
Thus the words that complete the blanks are hypothesis and experimentation.
