单项选择题
A．They get rid of intuition, B．They make it more logical. C．They reduce everything to numbers. D．They give an idea of the amount of error involved.
A．It is becoming more accurate. B．It is more accurate than the biological sciences. C．It is more accurate than some of the measurements of structural engineers. D．It is relatively inaccurate.
A．the skill of the scientist B．the extent to which variables can be controlled C．the requirements of the observer D．the development of more accurate instruments