Are you carrying too much on your back at school？Lots of kids at the same age are as you are.
Not only are students in China __16__from this problem，but kids in the United States are __17__ fed up with(饱受……之苦)heavy school bags.
Experts are starting to __18__ that more and more young students are having back and neck problems as a result of school bags __19__ too heavy for them.
