It can be inferred from the passage that global warming is _______.

A．there is an unseen hand controlling the earth's movement
B．there is an operating manual warning people against air-conditioning in the factory
C．people should prepare operating manuals to tell workers how to get greater comfort
D．people have been enjoying the most comfortable climate in Earth's history

A．It requires genuine police skills.
B．It can be justified.
C．It is crucial for the solving of a crime.
D．It over-estimates the police role but ignores the informant's role.