B1
an arrangement by which students and teachers from one country go to stay with students and teachers in another country
Dictionary examples:
During the exchange, I accidentally called my host mom 'teacher' for a month. (0.0)
Our school's exchange program accidentally sent students to Mars instead of Mars, Pennsylvania. (0.0)
In our exchange program, I taught my host family to eat pizza with chopsticks. (0.0)
Our school has an exchange with a school in Madrid, so I'll be going to Spain next semester. (29.0)