背景： 引起下肢静脉曲张的主要原因是() ["A．静脉瓣膜损伤","B．深静脉阻塞","C．静脉壁软弱","D．静脉压增高","E．髂静脉回流受阻"] EDTA盐抗凝剂不宜用于() ["A．凝血象检查和血小板功能试验","B．白细胞计数","C．血小板计数","D．白细胞分类计数","E．红细胞计数"] 检查静脉交通支瓣膜功能的试验有() ["A．Trendelenburg试验Ⅰ","B．Trendelenburg试验Ⅱ","C．Perthes试验","D．Prett试验","E．Buerger试验"] 可引起慢性肢体动脉缺血的病变有() ["A．多发性大动脉炎","B．布－加氏综合征","C．血栓闭塞性脉管炎","D．动脉粥样硬化","E．糖尿病"] 下肢深静脉血栓形成急性期可出现()