George struggled wildly, going under and resurfacing at regular intervals.乔治疯狂地挣扎，不断在水面上浮浮沉沉。Make a point of backing up your files at regular intervals.一定要定期备份文件。The cartridge must be replaced at regular intervals.弹药必须定时...
Precipitates are usually collected by centrifugation at intervals.常常是用离心法分段收集沉淀的.Try to get into the habit of eating at least three small meals a day, at equally spaced intervals.尽量养成每天至少吃3顿小餐的习惯，而且每餐的间隔要相同。She began to ...