validity例句
        Scientists are becoming increasingly unsure of the 
validity of this technique.
科学家们越来越拿不准这一技术是否正当合法。
The criticisms have at least an element of truth and 
validity.
那些批评至少有一丝真实性和合理性。
The period of 
validity of the agreement has expired.
本协议的有效期已过。