hit and miss
不确定的结果；可能成功或可能失败的情况
口语·形容结果不可靠
英文释义
something that is unpredictable or unreliable; often refers to a situation where success or accuracy is not guaranteed
例句
The Wi-Fi connection here is hit and miss; sometimes it works, sometimes it doesn't.
典故来源
源自射击或投掷运动，击中或未中完全随机，比喻结果不确定。