obscure [əbˈskjuə] a.不著名的；费解的 vt.使变模糊，掩盖

Since the two countries couldn’t ________ their differences, they decided to stop their negotiations. (99-34)
A) rectify
B) oblige
C) reconcile
D) obscure

Often such arguments have the effect of ________ rather than clarifying the issues involved. (02-12-70)
A) obscuring
B) prejudicing
C) tackling
D) blocking

Very few people could understand the lecture the professor delivered because its subject was very ________.(03-6-55)
A) obscure
B) indefinite
C) dubious
D) intriguing

Very few people could understand his lecture because the subject was very ______.(05-12-63)
A) faint
B) obscure
C) gloomy
D) indefinite

Keys: C. A. A. B