Translation:He is finishing his career in a zoo.
This is a non-sense statement. He finishes his career in a zoo. We would not say this in English. If you're saying that his last job is at a zoo, then it would be "He finishes his career at a zoo." If he's in a zoo, it means that he's in cage.
Maybe he got into a fight with his boss at a zoo that they went to together. While he threw punches at his boss, his colleague remarked, "He is finishing his career in a zoo."
Or perhaps he is retiring and his coworkers are throwing him a retirement party at the zoo.
Perhaps he is a banker and throws himself in a lion cage. Thus his also finishes his career in a zoo in english, but at the same time, he finishes his life....
Maybe not so odd in context. Perhaps he is a veterinarian who finished his career in a zoo.
The long and short of it is that the translation is poor English that no one, in any real context would say.
"After a tragic incident for both the lion and John Smith, and heavily celebrated by us, John Smith, a lawyer, finished his career at the zoo. He gave the lion indigestion.
What would be the context of this question? i.e. a retirement party in a zoo ( as previously stated ) say someone had a specific job, say a cleaner and his last assignment was in a zoo, he worked in a place that became a zoo, someone had several different jobs, the last of which was in a zoo?
To me it's straightforward: he works/is working in a zoo, and it's his last job. The omniscient narrator of an imaginary novel knows this.
Maybe it's metaphorical, like he is ending his career at a workplace that is way too crazy all the time, ie a zoo!
he is a circus owner of bygone era. due to present times and especially due to SPCA, he had to form a zoo to accommodate all his animals .Now his retirement time has come
The English "He is finishing his career in a zoo" makes it sound as though he left some other job (perhaps working for a vet) and will work for the zoo until he retires.
However, I strongly suspect that the French sentence means "He is ending his career at the zoo." We rarely say "a zoo" for something like this, much as we say "I went to the doctor" not "I went to a doctor."
Why is Duolingo obsessed with zoos ? In real life, conversations about the zoo are rare !