Well, you should make sure that the packet is made up in a strong cover and then, it is fastened with wax, gum or other adhesive substance.

嗯，你应该确保这个包是用结实的盖子盖好的，然后用蜡、口香糖或其他粘性物质固定。

Bacteria naturally tend to group together and stick to surfaces, and this creates an adhesive substance called " biofilm" , we see it every morning when brushing our teeth and getting rid of dental plaque, for example.

细菌自然倾向于聚集在一起并粘附在表面，这会产生一种称为“生物膜” 的粘附物质，例如，我们每天早上刷牙和去除牙菌斑时都会看到它。