问题补充：
Lucy felt on top of the world when she received the birthday present.
A. very excited
B. very lucky
C. very happy
D. very proud
答案：
A. very excited
B. very lucky
(答案→)C. very happy
D. very proud
解析：句意：当她收到这个生日礼物的时候，露丝感到非常高兴。on top of the world意思是，在世界之巅，在这里是幸福到极点,心满意足。意思是very happy.
