Answer:
Because people did not know that yellow fever was caused by the bite of an infected mosquito, they assumed incorrectly that people could catch the disease through touch. To help control the disease, letters were cleaned with vinegar before being sent. This did not work, because it was a false cause-and-effect relationship.
The Corona virus has changed our lives. It happened so fast and quickly, in one blink. Scientists have said that the virus is not new and has been around for a few years. Hopefully a cure is found soon for this. It is hard to see people dying from it and suffering from it every day.
If you're an auditory learner, it's best to learn by hearing things, so listen in class! :)
Some other techniques include recording yourself saying stuff that you need to know and playing it back and listening to that to learn it.
