1. I just heard that the girl I am obsessed with is going to get married.2. Fifty years ago I broke up with my first girlfriend. It was an unforgettable relationship.3. My wife and I have an extremely close relationship.4. When he found out his daughter was killed in a car accident, he started crying very hard.
 be obsessed with unforgettable extremely close hard死去活來有很多意思，請參考以下:這個讓我魂縈夢牽的女生 = a girl I am obsessed with 或 a girl who is constantly on my mind有一段很難忘的愛情 = an unforgettable relationship一直膩在一起的愛情 = an extremely close relationship哭的很難過 = cry very hard
這是一個連環問題: 燃燒石油導致二氧化碳增加，二氧化碳增加導致溫室效應，溫室效應導致冰層融化、海平面上升。 (請填空)
This is a chain of problems. Burning oil leads to increase in carbon dioxide, which leads to the greenhouse effect, which leads to melting of glacier, which leads to rising sea levels.