【题目】Kids don’t learn their native language , but they become fluent in them within a few years.
A．consciously
B．effectively
C．carefully
D．naturally
在线课程【答案】A
【解析】句意：孩子们无意识地学习母语，但几年之后，他们说得很流利。consciously
有意识地；effectively有效地；carefully小心地；naturally自然地。