During the investigation of a food poisoning incident, the doctor found out that the poisoned people who visited the same day had different foods, but everyone ate a mushroom sold at a farmer's market. Based on this, it was determined that the poisoning may be caused by the poison of this mushroom. Which of the following ways of reasoning are similar to the stem:. ['after research, scientists have found that the content of calcium in the hair of healthy people is on average higher than the content of calcium in the hair of people with myocardial infarction.', 'people found that foods such as steamed buns, rice, and meat products will deteriorate in the summer, and their textures are different, but because they are all in the high-temperature season, it is easy for bacteria to multiply. Therefore, high-temperature conditions are the reason for food deterioration.', 'rubbing hands can generate heat, hitting stones can generate heat, friction can generate heat, these are friction, there is no opposite case, so friction can generate heat.', 'by observing the penguin skiing posture, people designed a polar off-road vehicle that can reach a speed of 50 kilometers per hour and exceed the penguin speed.']