单选题 All sorts of technology have ______ to make the new medical systems applied in rural areas efficient and effective.
A. come into play B. come into conflict
C. taken action D. taken place

【正确答案】 A

【答案解析】[解析] 根据句中“各种技术都起了作用”可知，只有A项符合题意。come into play意为“开始起作用”。根据题意可知，A项为正确答案。