Decling revenues resulting from a decrease in business travel, a source of income without which most commercial airlines could not survive, are going to force many commercial airlines to increase prices and decrease services in the coming months.
a. a source of income without which most commercial airlines could not survive, are
b. a source of income without which most commercial airlines could not survive, is
c. and most commercial airlines use it as a source of income to survive with, are
d. which is a source of income which is needed by most commercial airlines who could not survive without it, are
e. which most commercial airlines use as a source of income without which they are unable to survive, is
a. a source of income without which most commercial airlines could not survive, are
b. a source of income without which most commercial airlines could not survive, is
c. and most commercial airlines use it as a source of income to survive with, are
d. which is a source of income which is needed by most commercial airlines who could not survive without it, are
e. which most commercial airlines use as a source of income without which they are unable to survive, is
