abacus的发明英语作文不用太多
问题描述：
abacus的发明英语作文
不用太多
答
Abacus was said to be invented by Guan Yu during the Three Kingdoms era of China.
答
An abacus,also called a counting frame,is a calculating tool used primarily in parts of Asia for performing arithmetic processes.Today,abaci are often constructed as a bamboo frame with beads sliding ...