periodically什么意思解释？

Periodically , the lamellae become enlarged, forming flattened, membrane - enclosed vesicles called thylakoids.片层周期性地扩展, 形成扁平的有膜为界的囊,称为类囊体.Mortality is the number or volume of trees periodically rendered unusable through...

Police were periodically patrolling the area.警察定时在这一地区巡逻。The geyser erupts periodically.间歇泉周期性地喷发.Economic crises recur periodically.经济危机周期性地发生....

periodically的音标：periodically的英式发音音标为：[ˌpɪərɪ'ɒdɪklɪ]periodically的美式发音音标为：[pɪrɪ'ɑdɪklɪ]...