TASK DEFINITION: You are given a sentence and your task is to generate another sentence that supports the given input.
PROBLEM: Some of these isotopes have half-lives of tens of thousands of years, and therefore require long-term isolation.

SOLUTION: The long-lived isotopes require thousands of years to decay to a safe level in a nuclear reactor.

PROBLEM: 30 Humans have 23 pairs of chromosomes;

SOLUTION: Humans have 23 pairs pairs of chromosomes.

PROBLEM: A scientific law always applies under the same conditions, and implies that there is a causal relationship involving its elements.

SOLUTION:
In science, something that always applies under the same conditions is called a scientific law.