pick from the following.
1). temperature
2). a pathogens
3). bacteria
4). h2o
5). mussels
6). oxygen
7). pollution
8). toxins
Given those answer options, answer the question: Fact 1: Treating water is used to remove harmful substances before drinking. Fact 2: Pollution is the release of harmful substances into the environment. Given the two facts above, what does treating water remove before drinking?
A:
7).