Question

19. In today's fast changing and competitive world, to be able to learn faster and more effectively is not merely desirable; it is   .

A. essential     B. worthwhile

C. challenging     D. sufficient

Answer 1

19. A考查形容词辨析。句意：在今天这个快速变化和有竞争力的世界中，能够学得更快、更有效不仅是可取的，也是基本的。essential基本的；worthwhile值得的；challenging有挑战的；sufficient充分的。选A。