男性2岁，原患营养性缺铁性贫血，近2周来发热，咳嗽.体格检查：T39.5℃，神萎，皮肤有猩红热样皮疹，气急，鼻扇，三凹征较明显，两肺散在中细湿啰音，肝肋下1.5cm.血Hb60g/L，RBC2.68×10¹²/L，WBC20×10⁹/L，N90%，L10%.胸片：右肺有肺大疱形成，已用青霉素丁胺卡那霉素，硫酸亚铁及维生素C等治疗.此时，最主要的治疗措施为（）

A.更换抗生素

B.改用右旋糖酐铁肌注

C.加用叶酸与VitB₁₂

D.输血

E.加强支持及对症治疗

Questions 17 to 20 based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions. Now listen to the passage.

hat is the percentage of the sugar used as food

A．19%.

B．90%.

C．10%.

D．30%.