n.病弱，伤残，不能自理，无效，失效

The contract became invalid due to the lack of a signature from one of the parties involved.
合同因涉及方之一未签字而变得无效。
The argument was quickly exposed as invalid because it was based on false premises.
该论点很快被揭露为无效，因为它基于错误的前提。
The passport had expired, rendering it invalid for international travel.
护照已经过期，无法用于国际旅行。
The scientific study was deemed invalid due to flawed methodology.
由于研究方法有缺陷，这项科学研究被认为无效。
His claim to the inheritance was declared invalid by the court.
他的继承权被法院宣布无效。
The voting process was criticized as invalid because of voter suppression tactics.
由于存在压制选民的手段，投票过程被批评无效。
The discount code you provided has expired and is therefore invalid.
您提供的优惠码已过期，因此无效。
The experiment's results were invalidated by the discovery of contaminated samples.
由于发现受污染的样本，实验结果被认定无效。
Her excuse for being late to work was invalid given that she had a history of tardiness.
考虑到她经常迟到，她上班迟到的借口是站不住脚的。
The hypothesis crumbled under scrutiny, revealing its invalidity.
假设在仔细审查下瓦解，暴露出其无效性。