The answer which is an example of a theme with a dual nature is D. people who work hard learn values but may not prosper.
The other sentences are pretty linear and expected - a person works hard and is successful in life. D is somewhat different, which is why it has two natures, or a dual nature.
Yes, because they give off unhealthy fumes that go into our atmosphere and harm our environment.
Answer:
Just thinking about all the things they'll be doing and all the fun they will be having can host their mood
