ANSWER : Mong

Explanation : . From the third sentence, it is clear that `Mong� stands for `and�.

ANSWER : Ding

Explanation : . Word `Attacking� is common in the first and third sentences, and the common code is `Ding�. Hence, `Ding� stands for `Attacking�.

ANSWER : Dong

Explanation : . In the first and second sentences, common word is `enemy� and common code is `Dong�. Hence, `Dong� stands for `enemy�

ANSWER : Ping

Explanation : . From the second and third sentences, it is clear that `retreating� stands for `Ping�.