Where is the W.C.?; Where can I wash my hand?; Where can I add some powder?; Where is the toilet?; Where is the lavatory?; Where's the restroom? 厕所在哪里?
The nearest public conveniences are in West Street. 最近的厕所在西街。
牛津高阶第八版
美国韦氏词典
Dictionary.com
Free Dictionary
维基百科 (自由的百科全书)