To know which scenario was correct, the researchers needed to find a transitional form — with characteristics that fall somewhere between bottom-dwellers and the permanently 'rafting' janthinids.
为了研究出哪种猜想是正确的，研究人员需要找到过渡类型，既有底栖蜗牛的特性也有漂浮泡泡蜗牛的特征。
2
When anchoring, holding ground refers to the bottom and its characteristics.
在下锚时，holding ground指的是水底的地面以及它的性质。
3
One important characteristics of China's traditional culture of law is to restrict and humiliate merchants, keeping them at the bottom of the four social strata.