【Inthepast，AmericansusedtothinkoftheUnitedStatesasa"meltingpot"ofimmigrants（移民）frommanydifferentculturestotheUnitedStates，theiroldwaysmeltedawayandtheybecamepartofacompletelynewculture．TheUnit】

问题描述：

In the past，Americans used to think of the United States as a"melting pot"of immigrants（移民） from many different cultures to the United States，their old ways melted away and they became part of a completely new culture．The United States was likened to a big pot of soup，which had bits of flavor（味道，滋味） from each different culture．All of the different cultures were so well blended（混合，掺杂） together that it formed its own new flavor．

Today，Americans realize that the simple"melting pot"theory is less true．Instead，different groups of people keep many of their old customs．Often groups of Americans from the same culture band together．They live together in distinctive communities，such as"Chinatowns"or"Little Italy"-areas populated almost exclusively（惟一，仅） by Americans of a single ethnic group-which can be found in many large American cities．Living in ethnic neighborhoods gives new Americans the security of sharing a common language and common traditions with people who understand them．

In time，however，people from different backgrounds mix together．They also mix with native-born Americans．Old traditions give way to new customs．The children of immigrants are often eager to adopt new，American ways．They often want to dress in Americanfashions，to speak English and to followAmericansocial customs．By one estimate（估计），about80percent of European immigrants marry outside their own ethnic groups by the time they reach the third generation．Third generation means that their great-grandparents were immigrants．Yet as successive generations become more"Americanized"，they often retain significant elements of their ethnic country．

28．What does the text mainly talk about？___

A．The American way of life．

B．Immigrants and native-born Americans．

C．Old traditions and new customs．

D．The multi-cultural society of the United States．

29．Why does the author mention"C