The purposes of the certificate are considered valid if the certificate has no key usage or if the key usage supports digital signature or nonrepudiation 如果证书没有密钥用法或如果密钥用法支持数字签名或认可，则认为该证书的用途有效。
This can either replace an existing key / value pair with the same key value , or insert a new key / value pair ( if no key with the same value existed ) 这(操作)要不用新键值取代已存在的具有相同键的键/值对，要不插入一个新的键/值对(如果不存在相同的键) 。
The second factor in chelsea ' s favour is that they have no key man whose loss through injury or suspension would significantly diminish their effectiveness 切尔西的第二个有利因素是，他们不会因为某个关键人物由于伤病或是停赛不能上场而严重削弱其实力。
Some people think , comparing with the international giants , such as motorola , nokia , the chinese enterprises have no key technology . their brands are much poorer . there is no way for the chinese enterprises to compete with the foreign companies ; some people think , chinese mobile phone enterprises can improve very quickly , just like the color tv set industry in the middle 1990 ' s 目前关于国产品牌手机的讨论很多，有的人认为，国产品牌手机先天不足，缺乏核心技术，在跨国公司垄断市场的情况下，无论技术、品牌方面部无法与之抗衡，根本就没有出路；也有的认为，国产品牌手机发展迅速，完全可以依靠自己的优势，象当年的国产彩电一样，在几年之内，迅速抢占市场，最终把洋品牌赶出中国市场。
