华法令抗凝机理是：
A．依赖AT3，抑制多种凝血因子
B．络合钙离子
C．抗血小板
D．抑制凝血酶活性
E．拮抗维生素K
参考答案：E
Only when _________ in the afternoon ________ able to leave.
A．the match was over; they were
B．was the match over; were they
C．was the match over; they were
D．the match was over; were they
农田作物的生长和土壤养分之间有着密切的关系，其产量往往受土壤中供应最不足的营养元素所制约。这是 ( )
A．李比希最小因子定律B．谢尔福德耐性定律C．阿伦法则D．贝格曼法则
