【单选题】( )is produced by mixing a small amount of an air-en-training agent with ordinary Portland cement.
C.
Air-en-training cement
【简答题】以下关于RFID中间件的描述中,正确的是( )。A. RFID中间件包括应用接口、核心处理接口及设备接口 B. 多读写器与多种应用的系统中,需要有一个连接RFID硬件与RFID应用的中间软件 C. 即使采用中间件编程,对于不同的RFID标签,其应用编程也不相同 D. 设备接口在RFID硬件与核心处理器之间起到了缓冲与保护的作用
【单选题】____________ I arrived in South Africa , I was struck by the very great difference in the atmosphere of the country.
【单选题】____________ I arrived in South Africa, I was struck by the very great difference in the atmosphere of the country.