4.下列何種中間產物不存在於克柏氏循環(Kerbs cycle)中?(A)乙醯輔酉每 A(acetyl CoA)(B)磷酸甘油酸(phosphoglycerate)(C)檸檬酸(Citrate)(D)琥珀酸(succinate)(E)蘋果酸(malate)