operational time的用法和樣例：
例句
- Afterwards, the proliferation activity of fibroblast was decreased along with the time of culture and the increase of doses of fluoride.
隨著(zhù)氟質(zhì)量濃度的增加和氟作用時(shí)間的延長(cháng)，成纖維細胞的增殖活力明顯減弱。 - The electromagnetic intensity, the acting time and the heat effect are the main factors which influence the separating result.
磁場(chǎng)強度及作用時(shí)間及磁場(chǎng)的熱效應是影響分離效果的主要因素。
