GRE Reading Comprehension: ETS-GRE阅读ETS - 9OL3WR492Z76VT5H7

Which one of the following can best be described as a supply-side element in the labor market, as such elements are explained in the passage? A. concentration of small businesses in a given geographical area B. need for workers with varying degrees of skill C. high value placed by immigrants on work D. expansion of the primary labor market E. development of an advanced capitalist economy