give the lie to something idiom
证明…不实
to prove that something is not true
The fact that the number of deaths from cancer in the area has doubled surely gives the lie to official assurances of the safety of nuclear power. 该地区的癌症死亡人数已经翻了一番，这个事实说明官方对核电安全性所作的种种保证纯属一派胡言。