$9.$ Which of the following is a primary use of aromatics in the petrochemical industry?

a$)$ Production of adhesives

b$)$ Manufacturing of pesticides

c$)$ Production of synthetic fibers

d$)$ None of the above

$10.$ What is the primary function of synthesis gas in petrochemical processes?

a$)$ Providing hydrogen for hydrotreating

b$)$ Serving as a precursor for methanol production

c$)$ Acting as a solvent in extraction processes

d$)$ None of the above

$11.$ Which of the following is a primary use of hydrogen in the petrochemical industry?

a$)$ Production of ammonia

b$)$ Manufacturing of cosmetics

c$)$ Production of asphalt

d$)$ None of the above

$12.$ Which petrochemical precursor is commonly used in the production of ethylene oxide, a key intermediate chemical?

a$)$ Ethylene

b$)$ Acetylene

c$)$ Butylene

d$)$ Propylene