We happen to age.
I can’t advise you what to do and what not to do — it’s a matter of _________.
I just wonder ________ that makes him so excited.
A new college is being built in ________ I can remember was an old factory 20 years ago.
A clean environment can help the city bid for the Olympics, which ________ will promote its economic development.
Letterboxes are much more ________ in the UK than in the US, where most people have a mailbox instead.