Can you explain ________ the sun goes down in the west?
If George keeps on working so hard, he’ll ______ sooner or later.
We, teenagers, have already had the ability to take care of our daily life __________.
I think she would appreciate ________ if we could all help out a bit more.
They moved to the country _____ their children could have a garden to play in.
The letter he had been looking forward to ________at last this morning.