crease mark造句

• The calf was at least 2 weeks old , as indicated by the absence of fetal folds which are believed to be the crease marks that remain along the dolphins side from being squashed inside its mother
  由于幼豚在母体内受到挤压，身体两侧会留下皱纹，因此从幼豚身上的出生标记已减褪的情况看来，当时它至少已有两周大。