hǎiyáng / shēngwùxuéjiā / tōngguò / guānchá / pángxiè / de / fùzhī / yùndòng / pànduàn / tā / shìfǒu / shòushāng海洋生物学家通过观察螃蟹的附肢运动,判断它是否受伤。Marine biologists determine whether a crab is injured by observing the movement of its appendages.