Complete the following sentence with a (compound) word derived from the one(s) given in bracket.
It is a(n) （ ） fact that we can secure peace only by preparing for war. (fortunate)
【正确答案】：UNFORTUNATE
【题目解析】：
根据前文a(n)和后文的fact，可知空处应该填形容词，fortunate为形容词，它的反义词为unfortunate，根据后文意思，我们只有对战争做好准备，才能保卫和平。所以应填unfortunate。句意：不幸的是，我们只有为战争做好准备，才能保卫和平。