larval duration的用法和样例：
例句
- While in their larval stage, giant clams must swim and feed in the water column.
当它们的幼虫期，巨蛤蚌必须游泳和喂养在水柱。 - Results Vasobral improved the development of larval and a dult stages,enhanced the vitality and increased the quantity and quality of ovum.
结果活血素能促进家蚕幼虫期生长发育，提高蛹期茧质量，延长雌蛾生命，并能产生更多卵子。
