单项选择题
A．skins that are quick to feel and respond B．skins that are delicate C．skins that are completely dry D．skins that are sticky or slippery
A．All senses have their limitations. B．Insects are more sensitive to colours than man. C．Man has not fully utilized all his senses. D．Man is not as good as animals in learning about the environment.
A．from the sense of direct touch B．through the difference in temperature C．through skin contact D．from the even distribution of pressure