Plans have been proposed ______ the largest dam in the world to be built along the Congo river.
It is reported that two schools, __________ are being built in my hometown, will open next year.
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.