Question

We had to wait half an hour _______ we already booked a table.

A. since
B. although
C. until
D. before

Answer 1

答案B
although 引导让步状语从句,意为“虽然”,表示“虽然我们订了座位,但是我们不得不等半小时”。since意为“自从”；until意为“直到”；before意为“在……之前”。