In order to let their children receive a better education, parents often have to ______ and for quite a long time.
It is pretty well understood ________ controls the flow of carbon dioxide in and out the atmosphere today.
A plan has been put forward ________ more graduates should go to work in the country.
After three hours'climbing,they reached ________ they thought was the place they'd been dreaming of.
John invited about 40 people to his wedding,most of ________ are family members.
When I arrived,Bryan took me to see the house________I would be staying.