The main purpose of the last line of the passage is to signal the reader that steps will follow.
In the first part of the passage, the author is giving some <em>background information</em> about the topic, which functions as an introduction to develop the main topic. The last sentence serves <em>to trigger</em> what the passage is actually concerned in, that is, the different ways in which contamination by this bacterium can be avoided. Thus, what the reader is expecting after the last line are some steps to follow.
I would say yes I have give a little cold bath to my notebook when it was raining and my mom didn't come to pick me up. so I had to run to my house from my school. Thank you.
Hmmmmmmmmmm let's see. have you tried bleach?
