Jim went to answer the phone. _____, Harry started to prepare lunch. [ ]

A. However

B. Nevertheless

C. Besides

D. Meanwhile

酸化肠内环境，减少氨的吸收形成的是（）

A.硫酸镁

B.左旋多巴

C.右旋多巴

D.乳酸

E.乳果糖