The operation of this gene in humans has not yet been demons...The operation of this gene in humans has not yet been demonstrated, however.选择与音频中某些词或词组意思相近的表达A、proved B、designated C、democratic
A
解析:
"本题考查音频中demonstrated与选项中proved的同义替换。
demonstrate [ ˈdemənstreɪt] v. 证明;表露
prove [ pruːv] v. 证明;检验
designate [ ˈdezɪɡneɪt] v. 指派;委任
democratic [ ˌdeməˈkrætɪk] adj. 民主的"