At the time of the earthquake Jeff was still in his office. He ________ to finish a project before he left for the day.
The reason for the party was _____ it was Sue’s birthday.
No sooner had we reached the top of the hill _____ we all sat down to rest.
I can think of many cases _____ students obviously knew a lot of English words and expressions but couldn’t write a good essay.
It is well understood _____ controls the flow of carbon dioxide in and out the atmosphere today.
–How far apart do they live? –_____ I know, they live in the same neighborhood.