[单选题]挣值等于( )
A.计划工作量×实际单价
B.已完工作量×实际单价
C.计划工作量×预算单价
D.已完工作量×预算单价

In the current immigration wave, something markedly different is happening here in the middle of the great American "melting pot." (46) There is a sense that, especially as immigrant populations reach a critical mass in many communities, it is no longer the melting pot that is transforming them, but they who are transforming American society.
American culture remains a powerful force—for better or worse—that influences people both here and around the world in countless ways. But several factors have combined in recent years to allow immigrants to resist, if they choose, the Americanization that had once been considered irresistible.
In fact, the very concept of assimilation is being called into question as never before. (47) Some sociologists argue that the melting pot often means little more than "Anglo conformity" and that assimilation is not always a positive experience—for either society or the immigrants themsel