Small sailboats can easily turn over in the water ________.

A．if not managed carefully

B．if are not managed carefully

C．unless not managed carefully

D．unless are not managed carefully

栓剂的检查（）

A．软膏剂 

B．颗粒剂 

C．胶囊剂 

D．注射剂 

E．药物制剂