885-15-14

12.B Because of the enormous research and development expenditures required to survive in the electronics industry, an industry marked by rapid innovation and volatile demand, such firms tend to be very large.

(A) to survive

(B) of firms to survive

(C) for surviving

(D) for survival（B）

(E) for firms’ survival

为什么 be required of sb to do ?

The subject of the main clause (such firms) presumes a prior reference to the firms in question. Furthermore, the logical subject of to survive and the logical complement of required should be made explicit. All three demands are met by B, the best choice. Choices A, C, and D, with no reference to the firms in question, meet none of these demands. In choice E, the illogical and awkward use of a prepositional phrase (for firms’ survival) buries the needed initial reference to firms in a possessive modifier.