There are two types of productivity, one is people and the other is tools. Tools are created by people. ——Mao Zedong

All tools and machines on the earth are nothing but the development of the perception of human limbs. ——Edison

It is accurate and concise in mathematical expression, abstract and universal in logic, and flexible in form. It is an ideal tool for communication in the universe. ——Zhou Haizhong

Innovation is the specific tool of entrepreneurs, that is, the means by which they use change as an opportunity to create a new industry and a new service. ——Drucker

Science is a powerful tool. How to use it, whether it brings happiness or disaster to people, all depends on the person himself, not on the tool. ——Einstein