____ that they are inexperienced, they have done a good job.

A．Giving

B．To give

C．Given

D．If given

属于水溶性碱性物质制成的盐，其本身不因pH变化而析出沉淀（）

A.硫酸阿托品

B.头孢菌素类

C.盐酸普鲁卡因

D.红霉素乳糖酸盐

E.维生素C