Wilkins Micawber is a character in the novel ______, an eternal optimist who, despite evidence to the contrary, continues to have faith that something will turn up.

A. aptitude test
B. proficiency test
C. achievement test
D. diagnostic test

A．all of the effects of pollution on the human body
B．how pollution can be controlled successfully
C．when the atmosphere first became polluted
D．how to wash the black snow clean