The planned military assault on the city yesterday was unaccountably delayed.原计划昨天对那座城市发动军事袭击，不知何故被推迟了。He suddenly, unaccountably, burst into tears.他突然莫名其妙地泪流满面。She was looking unaccountably upset.她看上去莫名地不安。And then, unaccountably, she giggled.接着，她莫名其妙地咯咯笑了起来。Leonard felt unaccountably happy.伦纳德感到一种说不出的高兴。