抗可溶性抗原的抗血清要长期保存，理想的方法是（）
A.液体4℃
B.低温
C.加叠氮钠
D.冷冻干燥
E.室温即可
参考答案：D
I think all the workers, ________ the leader _____ playing the most important role.
A．rather than ; are
B．rather ; are
C．more than ; is
D．less than ; is
何谓径流调节和兴利调节？水库的兴利调节计算需要哪几方面的基本资料？
