However, by 2001, none of the existing technologies provided adequate sensitivity, low white noise levels, or safe electro-magnetic emissions.
However, by 2001, none of the existing technologies provided adequate sensitivity, low white noise levels, or safe electro-magnetic emissions.
然而，在2001年以前，已有的技术都不能达到应有的敏感度，抗白噪音能力，及电磁发射安全性。