1. 迭合：summation formula 求和公式 | superimposing 迭合 | super set 母集

2. 迭加：superimposed layers 叠加层 | superimposing 迭加 | superisocon 分笼摄象管

3. 叠加：superimposed /上叠的/叠覆的/叠合的/叠加的/ | superimposing /叠加/ | superimposition /添加/重叠/

4. 叠和,叠合：summation formula 求和公式,总和公式 | superimposing 叠和,叠合 | supplementary angle 补角