A:在潮湿的酸性土壤中
B:在潮湿不透气的中性土壤中
C:在干燥致密不透气的土壤中
D:在潮湿透气的盐碱地中
A means a holiday, and people can do whatever they like during the holiday.
写出下列科学家的发现:
列文虎克;弗莱明;胡克