She hesitated for a fraction of a second before responding.她在回答之前犹豫了一下。She paused for a fraction of a second.她略微停顿了一下。If he'd reacted a fraction of a second later, he would surely have died.如果他当时反应稍慢一丁点儿，就必死无疑了。She hesitated for a fraction of a second before replying.她犹豫了片刻才回答。