unreliable

例句：

1. 1. He is not reliable as a source of information.
   他作为信息来源是不可靠的。
2. 2.The new software is unreliable and prone to errors.
   这款新软件不可靠，容易出错。
3. 3. The weather forecast is unreliable, so we should prepare for the worst-case scenario.
   天气预报不可靠，所以我们应该为最坏的情况做准备。