【单选题】Some observers have attributed the dramatic growth in temporary employment that occurred in the United States during the 1980's to increased participation in the workforce by certain groups, such as f...
A.
present the results of statistical analyses and propose further studies
B.
explain a recent development and predict its eventual consequences
C.
identify the reasons for a trend and recommend measures to address it
D.
outline several theories about a phenomenon and advocate one of them