Answer:
fall
rise
frictional
b. Improving a widely used job-search website so that it matches workers to job vacancies more effectively
Explanation:
A fall in the price of steel would reduce the profitability of producing steel for steel producing companies. Hence, the supply of steel would fall. as a result, less labour would be needed, so the demand for labour would fall.
A fall in the price of steel would reduce the cost of producing cars and thus increase the production of cars. as a result, more labour would be employed to make cars.
Frictional unemployment is when labour is unemployed between the time he leaves his current employment and time he finds another. by improving on the job search website, workers would be matched faster with available jobs, this frictional unemployment would decrease.