Complete the following sentence with a (compound) word derived from the one(s) given in bracket.
She could not give us a （ ） explanation for her decision to give up the opportunity. (reason)
【正确答案】：REASONABLE
【题目解析】：
根据前文a，后文explanation说明空格处应该填形容词，reason的形容词为reasonable有道理的，且符合句意。句意：她决定放弃这个机会没能给我们一个合理的解释。