The following points may help you:

a. Leeds and Manchester became important industrial centers.
b. Leeds emerged as an important mill centre during the phase of industrial development and attracted large migrant population.
c. Manchester also flourished because of cotton textile industries and expanded rapidly.
d. As trade flourished in these areas, further inventions like fly shuttle, spinning jenny began to be first used in their textile industries, in these cities that contributed to their industrial growth and prosperity.