Final answer:
A synonym for cascade is fall, which is true, and the word closest in meaning to hypothesis is suggestion, rather than a confirmed fact, law, formula, or conclusion.
Step-by-step explanation:
The synonym for cascade can be fall as they both refer to something moving downwards, often with water involved, so the answer is a. True.
As for the word closest in meaning to hypothesis, the correct choice is d. suggestion because a hypothesis is a proposed explanation made on the basis of limited evidence as a starting point for further investigation, rather than a confirmed fact, law, formula, or conclusion.