As the most frequently spoken language in the world Chinese in many schools in Europe.A.

问题补充：

As the most frequently spoken language in the world, Chinese in many schools in Europe.

A. is teachingB is taughtC. has taughtD. teaches

答案：

解析：考查时态语态：句意：作为世界上最常见的口语，汉语在欧洲的很多学校被教。因为是被动含义，排除ACD，选B。