a crucial test that proves the value or success of something
un test crucial qui prouve la valeur ou le succès de quelque chose (un test crucial qui prouve la valeur ou le succes de quelque chose)
"The product launch will be the acid test of our new design."
"Le lancement du produit sera le test acide de notre nouveau design." (Le lancement du produit sera le **test acide** de notre nouveau design)
to start over or make a fresh beginning
to feel extremely nervous or anxious
to do your share of the work or responsibility
to influence the outcome of a situation
to not succeed in doing something
a change in the way one feels about something or someone