Definition: used to show the time something happens Level: A1
今天下午2:30有个会议。
There's a meeting ___at 2.30 this afternoon.
你午餐时间有空吗？
Are you free ___at lunchtime?
理论上，女性在50岁时仍能生育。
In theory, women can still have children ___at the age of 50.
