It was about 600 years ago _____ the first clock with a face and an hour hand was made .
Today, we’ll discuss a number of cases __________ beginners of English fail to use the language properly.
The book was written in 1946, __________ the education system has witnessed great charges.
—Where did you get to know her? —It was on the farm __________ we worked.
Some pre-school children go to a day-care center, __________ they learn simple games and songs.
After graduation she reached a point in her career __________ she had to decide what to do.