Bacteria are carried by various 'media', which can include raw food, moist surfaces where bacteria have been left, our hands or skin and from coughing or sneezing (打喷嚏).
2018年12月四级真题（第三套）阅读 Section B
英语六级真题
Usually when we walk through the rain forest we hear a soft sound from all the moist leaves and organic debris on the forest floor," says ecologist Daniel Nepstad.
出自-2013年6月阅读原文
Even though the nuts, which need to stay moist, can be somewhat delicate to transport, traders carried them hundreds of miles throughout the forests and grasslands.