膝盖乌青了用英语可以说成 "The knee has become bruised and discolored."
"Bruised" 表示受伤，"discolored" 表示颜色不正常。膝盖乌青通常是因为受到了外力撞击或压力而导致的青肿。
下面是一些英文例句，并提供了中文翻译供参考：
"I fell off my bike and now my knee is bruised and discolored." (我从自行车上摔下来，现在膝盖乌青了。)
"I must have hit my knee on something because it's bruised and discolored." (我一定是膝盖撞到了什么东西，因为它乌青了。)
"I didn't reapze I had hit my knee that hard until I saw it was bruised and discolored." (我没有意识到我膝盖撞得那么重，直到我看到它乌青了。)
"Bruised" 表示受伤，"discolored" 表示颜色不正常。膝盖乌青通常是因为受到了外力撞击或压力而导致的青肿。
下面是一些英文例句，并提供了中文翻译供参考：
"I fell off my bike and now my knee is bruised and discolored." (我从自行车上摔下来，现在膝盖乌青了。)
"I must have hit my knee on something because it's bruised and discolored." (我一定是膝盖撞到了什么东西，因为它乌青了。)
"I didn't reapze I had hit my knee that hard until I saw it was bruised and discolored." (我没有意识到我膝盖撞得那么重，直到我看到它乌青了。)