单选题 20. The need for water and soil conservation was recognized during the latter part of the last century, and has been ______ developed in the American continent.

A、 excessively
B、 exceedingly
C、 extensively
D、 exclusively

【正确答案】 C

【答案解析】 上世纪下半叶人们认识到了保护水土资源的必要性，并在美洲大陆得以广泛发展。
副词辨析题。A“过量地，过度地”；B“极其，极度地”；C“广泛地，大规模地”；D“专门地，排他地”。从语义可知C为答案。