48 Although the two countries signed a _____ treaty about the borderline, it was soon violated by one of them.
(A) federal
(B) marital
(C) martial
(D) bilateral

Although the two countries signed a bilateral treaty about the borderline, it was soon violated by one of them.
儘管兩國簽署了有關邊界線的雙邊條約，但很快就被其中一方違反。

federal
relating to the central government, and not to the government of a region, of some countries such as the US
聯邦政府的
A federal system of government consists of a group of regions that are controlled by a central government.
聯邦（制）的
marital
connected with marriage
婚姻的
martial
relating to soldiers, war, or life in the armed forces
軍隊的;戰爭的;軍事的
bilateral
involving two groups or countries
雙邊的，雙方的