在颗粒凝集法中要稀释血清标本,原因是:()
A.防止假阳性
B.防止假阴性
C.节省标本
D.节约试剂
参考答案:A
人体有______块骨,______块骨骼肌.
"Take a look at these pictures, and see if you can _____ the criminal. " The policeman said to the witness.
A.pick up
B.pick off
C.pick out
D.pick at