Definition: to become blue, cold, nasty, etc. Level: B2
天空变黑，开始下雨了。
The sky ___turned black and it started to rain.
天气突然变冷了。
The weather has suddenly ___turned cold.
当我拒绝付款时，他变得暴躁起来。
When I refused to pay, he ___turned nasty.
