They were when they heard the news.
A. excited, exciting
B. exciting，excited
C. excited，excited
D. exciting， exciting
网友回答
(答案→)A. excited, exciting
B. exciting，excited
C. excited，excited
D. exciting， exciting
解析：excited兴奋的，指人；exciting令人兴奋的，指物；句意：当他们听到这个令人兴奋的消息时，他们太兴奋了。前文指人，下文指物。故选A。