无效

• Without the latter, the former is of no avail .
  没有后者，前者是无效的。
• They tried in vain to frighten him with threats .
  他们百般恫吓，依然无效。
• This medicine turned out ineffective .
  这药证明是无效的。
• A promise obtained by force is legally null .
  一个以武力获得的契约在法律上是无效的。
• All rescue measures proved ineffectual .
  抢救无效。
• A contract is invalidated if only one party signs it .
  如果只有一方签字，契约即无效。
• Our marriage is nothing .
  我们的结婚是等于无效的。
• A clog or fetter on the equity of redemption is void .
  阻碍和束缚衡平法上的赎回板均是无效的。
• This certificate is invalid .
  此证明无效。
• When a precedent is overruled the effect is retrospective .
  先例被宣告无效时，其结果溯及既往。