Fact 1: Some parasites kill their host, but most do not. Fact 2: Leeches are external parasites. Given the two facts above, some what will kill their host, while others won't?

1). barnacles.
2). producers.
3). scavengers.
4). insects.
5). cigarettes.
6). fungi.
7). plants.
8). leeches.
Answer:
8).