0 a substance that is colourless when it is mixed with an acid and pink or red when mixed with an alkali --
1 a substance that is colorless when it is mixed with an acid and pink or red when mixed with an alkali --
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
Можем да го завършим стъпка по стъпка, колкото и дълъг да е пътят и не може да бъде завършен, колкото и кратък да е пътят, ако дори не маркирате отпечатъка си.