单项选择题
The author says that he is a naturalist rather than a scientist probably because he thinks he （）
A．has a great deal of trouble doing mental arithmetic B．lacks some of the qualities required of a scientist C．just reads about other people's observations and discoveries D．comes up with solutions in a most natural way
单项选择题 The first paragraph tells us the author （）
单项选择题 30（）
单项选择题 29（）
