TASK DEFINITION: You are given a sentence and your task is to generate another sentence that supports the given input.
PROBLEM: A group of such cells is a tissue, and in animals these occur as four basic types, namely epithelium, nervous tissue, muscle tissue, and connective tissue.

SOLUTION: Four types of tissue are found in animals.

PROBLEM: A neutral atom has an equal number of protons and electrons so that the positive and negative charges exactly balance.

SOLUTION: Because atoms have equal numbers of positive protons and negative electrons, they possess a neutral charge.

PROBLEM: All mammals have four limbs.

SOLUTION:
All mammals have four limbs.