精品学习网考试频道小编应广大考生的需要，特为参加考试的考生策划了“PETS4写作精选短语：Acid test”专题等有关资料，供考生参考!
Acid test
a decisive, crucial test of something’s true worth or someone’s true abilities (coming from the use of nitric acid to test the authenticity of gold samples)
EXAMPLE:
“We liked the new manager, but we knew the acid test would be how she did when she opened our new office in San Francisco by herself.”