In this passage the word" departure" means _______.

A．She wanted to know who was the best student in the class.
B．She wanted to improve their writing ability.
C．She wanted to keep them in the classroom.
D．She wanted them to be proud of the country.

A．Tile higher one climbs, the less oxygen he will breathe.
B．The higher one climbs, the more dangerous it will be.
C．The faster one climbs, the less oxygen he needs.
D．The faster one's heart beats, the thicker one's blood becomes.