1、Viewing is by appointment only.
參觀須預(yù)約。

2、Free professional consultation by appointment is also available.
中心亦接受預(yù)約，提供免費(fèi)的專業(yè)諮詢服務(wù)。

3、Viewing of the house is by appointment only.
要看房只能提前預(yù)約。

by appointment翻譯