serum prothrombin

例句：

1. 1. The patient's blood was tested for the presence of serum prothrombin.
   病人的血液被检测以确定是否存在血清凝血酶原。
2. 2. The researcher found that serum prothrombin levels were significantly higher in patients with heart disease.
   研究者发现，患有心脏病的病人血清凝血酶原水平显著高于正常人。
3. 3.The doctor administered an injection of vitamin K to correct the patient's low serum prothrombin levels.
   医生给病人注射了维生素K来纠正其低血清凝血酶原水平。