With more and more farmers moving to cities, an inadequate labor force is being a major factor affecting the country's grain output.
A. automatically
B. occasionally
C. absolutely
D. gradually
网友回答
A. automatically
B. occasionally
C. absolutely
(答案→)D. gradually
解析：答案：D 考查副词词义辨析。句意为：随着越来越多的农民搬到城市，劳动力不足逐渐成为影响这个国家谷物产量的主要因素。automatically意为“自动地，机械地，无意识地”；occasionally意为“偶尔，间或”；absolutely意为“绝对地，完全地”；gradually意为“逐步地，逐渐地”。根据语境可知，空格处表示的是一种过程，gradually的词义与此相符。故答案选D。