Cracking? ? Unification? ?Alteration
8. B
9. C
10. A
11. A? 本題可以在F段的第三句話找到答案 In the cracking unit, large hydrocarbon chains are broken into smaller ones.
12. C
13.? B?本題也可以在F段找到，Platinum or platinum-rhenium is often used in chemical manufature and blending gasoline.
