Part 1. Definition
You are given a science question (hard-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.
Part 2. Example
Which event can cause a large rock to become soil over time?
(A) decaying (B) an earthquake (C) a landslide (D) weathering
Answer: D
Explanation: Under the action of heat, cold, rain, wind, and other atmospheric factors, the rock breaks down physically into small fragments that become the parent material of the soil. Also, atmospheric factors change according to weather.
Part 3. Exercise
Many bacteria grow quickly at room temperatures of about 20C. The temperature inside a refrigerator is usually kept at about 4C. Which statement best explains how using a refrigerator has helped society?
(A) It keeps kitchens cooler in the summer. (B) It provides more space for food storage. (C) It makes food safer to eat for longer periods. (D) It makes electricity safer to use in the kitchen.
Answer:
C