instruction:
Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.
question:
Question: What part of the cell helps it keep its shape? Answer: cytoskeleton
answer:
cytoskeleton. This is a network of fibers and tubules that crisscrosses the cytoplasm. The cytoskeleton helps the cell keep its shape.

question:
Question: Lactic acid fermentation is common in muscle cells that have run out of what? Answer: oxygen
answer:
Figure 7.14 Lactic acid fermentation is common in muscle cells that have run out of oxygen.

question:
Question: How many different types of stresses are there? Answer: four
answer:
Stress is the force applied to a rock. There are four types of stresses:.