The main idea of the second paragraph is______. A．diversity of the workforce has its disadvantages B．besides new opportunities, the changing workforce also contain challenges C．the low educational levels of immigrants is a challenging problem D．America had better face the problem of declining skills or it will suffer
A. A．diversity B.besides C.the D.America
【参考答案】
B 属主旨思想题，考查第二段的大意概括。第二段重点涉及美国劳动力构成变化存在的问题，B正确。C项以偏概全，不够全......