This book is the perfect______to the seven continents.
A. produce
B. production
C. reduce
D. introduction
I always dreamed of becoming the _____of an orchestra.
A. production
B. conduct
C. conductor
D. semiconductor
withdraw 的意思是?
A. 撤回
B. 后悔
C. 删除
D. 绘画
downstairs 的反义词是?
A. indoors
B. outdoor
C. upstairs
D. outdoors