drop-in substitute随手可得的代用品
Drop-in Center收容中心
Drop - in Visitors不速之客
drop-in office急诊处
information drop-in信息混入
Drop-in Visitors不速之客
window drop-in叠印框
drop-in tool投入工具
drop-in test混入测试
ADJ（形容词） Drop-in centres or services provide information and help for people with particular problems, usually on a free and informal basis. 免费提供信息和帮助的(中心或服务) [ADJ n]
...a drop-in centre for young mothers.
...为年轻妈妈们免费提供信息和帮助的活动中心。