1. The advertisements declare that active ingredients stimulate cells deep in the skin's layers to divide, so replacing old cells and effectively renewing the skin.
    广告声称那些活性因子能刺激皮肤深层的细胞分裂，以此来替换旧细胞，并有效地更新皮肤。

2. Pierce J. Howard, another expert, says new research indicates that physical exercise increases the amount of certain brain chemicals that stimulate growth of nerve cells.
    另一名专家皮尔斯·J. 霍华德说，新的研究表明，体育锻炼提高了大脑中某些激发神经细胞生长的脑化学物质的含量。

3. It failed to stimulate a surge of investment in industry.
    这没能促使工业投资激增。