No, there shouldn’t be a spaces behind commas and you don’t need this part:
But I can see that there are still quite big errors on those distances (2 - 4 cm). Are the distances measured correctly?
No, there shouldn’t be a spaces behind commas and you don’t need this part:
But I can see that there are still quite big errors on those distances (2 - 4 cm). Are the distances measured correctly?