To persuade the consumer to get the item for a reason.
Answer:
Hudson river have a different climate and is not inhabitable by zebra mussels was said by scientist in the 90s. It might be because of increasing water pollution in the Hudson river as their are channels from the cities which meet the river.
Formal is used in situations that are more serious. For example when you're in a job interview or emailing your professor. It can also be used when you're speaking to someone you don't know very well and want to make sure you sound respectful.
Informal is used in a more relaxed, everyday situation. This includes conversations with friends, family and other people you know well.
