Definition: a length of time Level: B1
你在那里待了一段时间，不是吗？
You were there ___a ___while, weren't you?
过了一会儿，罗伯托回来了。
After ___a ___while, Roberto came back inside.
我有一段时间没见到他了。
I haven't seen him for ___a ___while.
