Americans today believe that acceptable social behavior. follows effortlessly from persona

l virtue. The (1)_____ between morals and manners has become blurred. (2)_____ you need is a good heart, most people assume, and the (3)_____ will take care of itself. You don't have to write thank-you notes.

Many Americans believe that natural behavior. is beautiful. The "natural" (4)_____ to human relations presumes that to know any person well enough is to love him, that the (5)_____ human problem is a communication problem. This (6)_____ that people might be separated by basically, generally irreconcilable differences—philosophical, political, or religious—and assumes that all such differences are (7)_____ misunderstandings.

Indeed, it has never been easier to insult people inadvertently. A gentleman opens a door for a lady because his mother taught him that ladies (8)_____ such courtesies, but she (9)_____ and spits in his eye because he has insulted her womanhood. A young lady offers her seat in a (10)_____ bus to an elderly, frail gentleman, and he gives her a (11)_____ look because she has insulted his (12)_____ Mind you, those are just people (13)_____ to be nice; the only problem is that they are (14)_____ on different systems of (15)_____.

Curiously, it has never been (16)_____ to insult people intentionally. If you say, "You are nasty and I hate you," the person is (17)_____ to reply, "Oh, you're feeling (18)_____; I'll wait until you feel better. "

The idea the people can behave "naturally" without resorting to a(n) (19)_____ code tacitly agreed upon by their society is as silly as the idea that they can communicate by using a language without (20)_____ accepted semantic and grammatical rules.

A．instinct

B．distinction

C．intuition

D．similarity