单项选择题
A．he didn't live very long with them B．the family was extremely large C．he was too young when he lived with them D．he was fully occupied with observing natur
A．a scientist as well as a naturalist B．a naturalist but not a scientist C．no more than a born naturalist D．first of all a scientist
A．full of ambition B．knowledgeable C．full of enthusiasm D．self-disciplined