这里填什么 is an early form of calculatorIt is a frame with rows of beads around the rods that are used for four fundamental operations of arithmetic
An abacus.
原文地址: https://www.cveoy.top/t/topic/bCfd 著作权归作者所有。请勿转载和采集!
- 上一篇: 真核细胞核糖体60S和40S为什么组成的是80S
- 下一篇: 静电纺丝法原理