red education science thumbtack office temperature effect energy work physics heat solar hash greenhouse infra-red infrared infra Greenhouse Effect clip art 温室 影响 学校 红色教育科学图钉办公室温度影响能源工作物理热太阳能哈希温室红外线红红外红外线
These symbols created to be used in creating electroschemes. In preview you see only small part, also thumbnail generator rendered charactaer wrongly :s 电 符号 电阻 Electrotehnic 符号 v0.1
This image was donated by Pearson Scott Foresman, an educational publisher, to Wikimedia Commons, and is thereby in the Public Domain. --- See http://commons.wikimedia.org/wiki/Category:Pearson_Scott_Foresman_publisher 动物 哺乳动物 马 马计划