Tom was very angry about ________ to Mary’s birthday party.
I have seen trees, _____ open at sunrise and close at sunset.
___ is known to all, China is a developing country, belonging to the third world.
She showed her new watch to my wife, ___ was kept in a box.
The reason ______he didn't come was ______he was ill.
We travelled together as far as Chicago, _______ we parted.