.— When did they come back last night?— It was midnight ____ all of us were sleeping.
There is no simple answer,________ is often the case in science.
John invited about 40 people to his wedding,most of________are family members.
We have launched another manmade satellite, ________is announced in today’s newspaper.
Many countries are now setting up national parks________animals and plants can be protected.
When I arrived,Bryan took me to see the house________I would be staying.