题目

生物体内葡萄糖分解代谢过程的图解如下。请据图回答：(1)图中A是________，其产生的部位是________。(2)反应①②③④中，必须在有氧条件下进行的是__________；可在人体细胞中进行的是__________。(3)苹果贮藏久了，会有酒味产生，其原因是发生了图中________过程。(4)如果有氧呼吸和无氧呼吸产生等量的CO2，所消耗的葡萄糖之比为____________。Wait a moment. The director _____ her assistant pick up some sandwiches for the meeting.A. has B. has had C. had had D. was having