单选题 However, unfulfilled ______ of technology application have created a gap between earth observation services and the application markets not integrated into the economic mainstream.
【正确答案】 B
【答案解析】[分析] 词义辨析 A．charges 负荷，费用，充电；B．pledges 保证，誓言，抵押；C．mergers合并；D．charts图表，海图；本句意为：然而，技术应用未能兑现承诺造成在地球观测服务领域与未能融入经济主流的市场应用之间形成缺口。在此unfulfilled pledges 是固定用法，表示：未能兑现承诺；因此B为答案。