reasoning questions

Question 1: Penguin Meat A male scientist recalls: he and his friend went on an expedition to Antarctica, but he got snow blindness halfway and couldn't see anything. So they wandered in Antarctica and eventually had to eat penguins raw to survive. However, his friend didn't make it in the end and died. He continued walking alone for a day and was finally rescued. The next day, he intentionally went to a penguin restaurant to eat penguin, but after returning, he unexpectedly committed suicide. Why?

Question 2: Jumping from the Train A man took a train to a nearby town for medical treatment, and after the treatment, he was fully cured. On the way back, the train passed through a tunnel, and the man jumped from the train to commit suicide. Why?

Question 3: Water Plants A boy went for a walk by the river with his girlfriend. Suddenly his girlfriend fell into the river, and the boy hurriedly jumped into the water to search for her, but couldn't find her. Heartbroken, he left. Years later, he revisited the same place and saw an old man fishing, but the fish caught did not have any water plants on them. He asked the old man why the fish didn't have any water plants on their bodies, and the old man said: "This river has never grown water plants." Upon hearing this, the boy suddenly jumped into the water to commit suicide. Why?

Question 4: The Funeral Story There were three women: a mother and two daughters. The mother died, and the two sisters went to the funeral. At the funeral, the younger sister met a very handsome man and fell in love at first sight. After returning home, the younger sister killed her older sister. Why?

Question 5: Half a Matchstick A man was found dead face down in the desert, with several suitcases scattered around him, and he was tightly holding half a matchstick in his hand. Deduce how this person died.

Question 6: Sawdust on the Ground In a circus, there were two dwarfs. The blind dwarf was shorter than the other dwarf. The circus only needed one dwarf, and obviously, the shorter the dwarf, the better. The two dwarfs decided to compete to see whose height was shorter, and the taller one would commit suicide. However, the day before the height comparison, the blind dwarf, who was the shorter one, had already committed suicide at home, leaving a lot of sawdust on the floor. Why did he commit suicide?

Question 7: Midnight Knock A man lived in a small cabin on the mountaintop. Late at night, he heard knocking at the door. He opened the door but no one was there and went back to sleep. After a while, there was knocking again, he opened the door, still no one, and this happened several times. The next day, a corpse was found at the foot of the mountain, and the police took the person from the mountaintop away.Why?
Question 8: The Cow Eats Grass.
There was a young man whose house had a lawn separating it from the neighbors' house. One late night, the man was awakened by the sound of an argument next door. After that, he heard the sound of things being thrown, the chopping of knives, and the sound of a cow eating grass. After a while, he also heard someone banging on his door, but he ignored it and went back to sleep. The next day, he discovered that the woman next door had been tragically murdered at his doorstep. Deduce the process.