Teachers have to constantly update their knowledge in order to maintain their professional ___.
A. consequence
B. independence
C. competence
D. intelligence
促进国际服务贸易迅速发展的主要原因是()
A. 产业结构的调整
B. 新科技革命
C. 国际货物量的增加
D. 各国服务业比较优势的差异
In that school, English is compulsory for all students, but French and Russian are _________.
A. special
B. regional
C. optional
D. original
我国累计技术引进最多的贸易伙伴是()
A. 日本
B. 美国
C. 欧盟
D. 以色列