Mr Brown is a(n) secretary in our office, for he is able to do tasks successfully, without wasting time and energy.
A. effective
B. efficient
C. flexible
D. sufficient
网友回答
A. effective
(答案→)B. efficient
C. flexible
D. sufficient
解析：考查形容词辨析。A有效的；B高效的；C灵活的；D充分的；句意：布朗先生是一个很高效的秘书，因为他能够成功完成各种任务，而且不浪费时间和精力。根据句意说明B正确。