答案:【计分规则】: (1) If a certain reaction is essential for the toxic mechanism to be carried out, a structural change could be made to ensure that the reaction could not take place. At the same time, any structural modifications would ensure that the function and performance of the molecule were still preserve.(2) If the mechanism is not known, looking for the correlation existed between chemical structure and the toxic effect. The functionality related to the toxic effect would be avoided, minimized, or eliminated to reduce or eradicate the toxic end-point.(3) Minimizing the bio-availability: If a substance is toxic, yet cannot reach its target organ where its toxicity would be manifested, then it is rendered innocuous.