On a Cisco Aironet 1240AG Series standalone access point， the radio LED is dark blue and blinking，but the status LED and Ethernet LED are both off. What does this indicate？（） ["A firmware upgrade is in progress.","An access point buffer overflow is occurring.","The internal radio has failed.","The access point is booting."]
简述在分离黄酮化合物时，影响聚酰胺吸附力强弱的因素？
点火提前角过（），易发生爆震。所以，当发生爆震时，可通过（）点火提前角来抑制爆震。
2014年我国零售支付主要使用现金。全国社会商品零售总额中有（）的交易是用现金支付的。 ["20%","13%","5%","80%"]
随着转速的升高，汽油机点火提前角自动调节装置使点火提前角（）。
什么是自动识别技术？自动识别技术包括哪些类型？
