What are you going to do Saturday morning?[ ]
A. at
B. on
C. in
答案:B
早产新生儿死亡率为
A.25%
B.5%
C.15%
D.1%
E.20%
下列化合物中具有抗恶性疟疾作用的是()
A.薄荷醇
B.龙脑
C.青蒿素
D.紫杉醇
E.甘草酸