问题

It’s over twenty years ______ we met lastCan we recognize each other when we meet at the airport?[ ]

A: before
B: until
C: since
D: once

正确答案是：

同类题型

We haven’t settled the problem of ________ it is necessary for him to study abroad

Excuse me, I’d like a pair of shoes. －What about this _______ You can try ______ on.

The WTO cannot live up to its name ______ it does not include a country that is home to one fifth of mankind　　[ ]

_______he really means is ________hedisagrees with us.

How was your hometown —Great changes took place.