单选题 The policemen threaded their way through the building to look for a gunman______.
【正确答案】 D
【答案解析】解析：句意：警察们穿过大厦为了寻找一位持枪在逃歹徒。at large在逃。at times有时，偶尔。at heart本质上，内心里。at ease安逸，舒适。