进行变压器耐压试验用的试验电压的频率应为()Hz。
A. 50
B. 100
C. 1000
D. 10000
我国汽油规格要求实际胶质含量不得大于5毫克/100克。
A. 正确
B. 错误
One of the main advantages of a graphite-furnace atomizer is that()
A. It requires only very small quantities of a sample
B. It requires metal.ions in aqueous solution
C. It does not produce background emission like a flame
D. It does not get hot like a flame
406MHZ EPIRB中含有121.5KHZ发射频率,该频率主要用于()
A. 定位
B. 发送识别码
C. 供飞机寻位
D. 供SART寻位