美国华人社会自上世纪70年代以来经历了巨大的变化。最显著的变化是随着许多中国人不断涌入美国，美国华人经济得到快速增长。美国华人家庭的年均收入已超过美国白人家庭。而且，近年来在美国如雨后春笋般涌现了一批杰出的华裔科技人才。他们的成就引起了世界上科学家和技术专家的注意并得到了赞赏。同时华人的政治地位也得到了显著提升，步入美国政治圈的华人逐渐增多。

参考译文：

Since the 1970s the Chinese community in the USAhas undergone tremendous changes.The mostremarkable change is its rapid increase in economyas many Chinese have kept flooding intoAmerica.Chinese American family's annual averageincome has overtaken that of the US white family. And, prominent scientific and technical havetalents of Chinese descent have sprung up in the US in recent years.Their achievements haveattracted attention and gained admiration of scientists and technical experts in the world.Meanwhile,more Chinese Americans enter American political circles as they have risen evidentlyin political status.