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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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