Don’t believe in those ads that you can master a language in one month. Instead it is a(n

问题补充：

Don’t believe in those ads that you can master a language in one month. Instead, it is a(n) process, which may last for years.

A. rapid

B. instant

C. gradual

D. regular

答案：

A. rapid

B. instant

(答案→)C. gradual

D. regular

解析：考查形容词，rapid迅速的 instant即时的 gradual逐渐的regular有规律的

句意为，不要相信那些说可以在一个月内掌握一门语言的广告，相反，这是一个逐渐的过程，可能需要几年的时间。