Mr Brown lives in a nice house in a small town with his wife(妻子), Mrs Brown. From Monday to Friday he works in an office near his house. He is free on Saturdays and Sundays. He has a nice garden beside his house. He likes growing flowers and he often works in the garden on Saturdays and Sundays. The flowers are very beautiful and Mrs Brown likes them very much. She often helps Mr Brown.

下列有关以下物质的工业制法中，正确的是（　　）

在物理实验中，对物理量进行多次测量，有的是为了通过多次测量减小误差，有的是为了通过多次实验寻找规律．其中为了减少实验误差的是（　　）

通过利用细菌可以生产____，利用细菌生产____。