TASK DEFINITION: You are given a sentence and your task is to generate another sentence that supports the given input.
PROBLEM: The principle of superposition states that in an undisturbed stack of sedimentary strata the oldest layer is at the base and the youngest at the top.

SOLUTION: The law of superposition is best described by: in undisturbed layers of sedimentary rock, the lowest layers contain the older rocks.

PROBLEM: The three tissue types are vascular tissue, including phloem and xylem, which are responsible for conducting materials through the plant;

SOLUTION: Modern plants have three types of major tissues.

PROBLEM: A lymph node is actually part of the immune system.

SOLUTION:
Each lymph organ has a different job in the immune system.