分析：第一个shall不可能表示“必须”（意思不通），所以不能换成must；换成will又不符合法律使用一般现在时的原则，所以只能换成is；第二个shall 表示应当(必须），所以，要译为must。

拟译：

A contract drawn up in accordance with the law is legally binding upon the parties. A party must perform its obligations in accordance with the contract, and may not arbitrarily modify or terminate the contract.

旁证：A contract validly entered into is binding upon the parties. It can only be modified or terminated in accordance with its terms or by agreement or as otherwise provided in these Principles.

例2. 

第七条有下列情形之一的，禁止结婚： 

(一）直系血亲和三代以内的旁系血亲；

(二）患有医学上认为不应当结婚的疾病。 

原译：

Article 7 No marriage shall be contracted under any of the following circumstances：

(1) if the man and the woman are lineal relatives by blood，or collateral relatives by blood up to the third degree of kinships; and

(2) if the man or the woman is suffering from any disease，which is regarded by medical science as rendering a person unfit for marriage. (中国法制出版社）

拟译：

Article 7 Marriage is prohibited if ---

The two parties are lineal relatives by blood, or collateral relatives by blood up to the third degree of kinship; or 

Any party suffers from a disease considered by medical science as making a person unfit for marriage.

如果像原译那样，用否定的表达方法，应该说No marriage may be contracted... ,而不是 shall be...。

责任编辑：admin