range of tools we use is amazingly wide.(1)Tool use was once thought to be one of the
features that set humans apart from other animals. To be sure, humans have developed
and used mechanical, electric and electronic tools for multiple purposes.(2)In no other
animals can we see such sophisticatedand elaborate use of tools.
To us humans tools are
an important (b)(1.meaning 2.means) to control and manipulate our physical environment.
(C)(1.During_ 2.While ) the development of civilization, humans'use of tools has
improved and diversified. We humans not only use tools but make and develop a variety of
new ones for different purposes.
We can(d)(1.even 2.ever ) use tools to make other
specific tools. In addition, the use and making of tools is handed down from generation to
generation. Tool use by humans is not genetically transmitted by DNA (e)(1.and 2.but)