Hedonic adaptation means people always return to their usual level of happiness after the temporary satisfaction.

A．Americans were much concerned about and well prepared for the possible threat.
B．Nuclear plants were the most important places that need protection.
C．Washington, DC would be perfectly safe under the protection of surface-to-air missiles.
D．These protective methods will make Americans less worried about the possible treat.

A．It is said that only big states and cities will be in danger this time.
B．Americans have not talked too much about the possible threats.
C．It is said that Los Angeles is particularly in danger this time.
D．The aim of terrorism is to make Americans feel unsafe wherever they are.