hemisphere – n. a half of the Earth, usually divided between the northern and southern halves

emphasize –v. to give special importance or attention to something

razor's edge –n. a dangerous position in which two different things are carefully balanced

respiratory –adj. related to breathing and the lungs

humid –adj. when there is a lot of gaseous water in the air

skyrocket –v. to go up or increase at a very fast rate

anticipate –v. to expect something to happen in the future

dose –n. an amount of a medicine needed to give a good result

mild –n. not severe or strong