Complete the following sentence with a (compound) word derived from the one(s) given in bracket.
To him, friendship is nothing but a promise of（ ）and unselfishness. (loyal)
【正确答案】：LOYALTY
【题目解析】：
根据前文a promise of（···的承诺）说明空格处应该填名词，loyal的名词形式为loyalty忠诚，符合句意。
句意：对他来说，友谊不过是忠诚和无私的承诺。