He had been good terms with Tom but all of sudden they lost in touch with each other.A.

问题补充：

He had been good terms with Tom, but all of sudden they lost in touch with each other.

A. on ; a

B. in ; /

C. on ; the

D. in ; a

答案：

(答案→)A. on ; a

B. in ; /

C. on ; the

D. in ; a

解析：考查固定词组。In good terms with sb与某人关系好；all of a sudden突然；句意：他曾经和Tom关系很好。但是突然他们就失去了联系。故A正确。