### Chinese: 那么大家肯定会问：为什么袋装保质期是一年，而听装的保质期是两年或更长呢？
### English: Then people will definitely ask: Why is the shelf life of bagged bags one year, while the shelf life of tinned bags two years or longer?
### Errors: There is a major error at "bagged bags". There is a major error at "tinned bags".

### Improved English: Then you may ask: why is the shelf life of milk powder one year in bags and two years or longer in cans?