We breathe in ...
oxygen
we breathe out ...
carbondioxide
this is the ...
respiratory system
when we run, our breathing is ...
heavy/fast
what is this?
nose
what are these?
nostrils
what is this?
windpipe/trachea
the ... lung is smaller to give space to the heart
left
the left lung is smaller to give space to the ...
heart
what are these?
bronchi
what are these?
lungs
what is this?
diaphragm
