参考答案

正确答案：A
解析：fall into a slumber 文学作品中常表示睡觉的意思；slumber “睡眠、微睡”如：“He awoke from a deep slumber.”；fatigue“疲劳”n.& v.如：“His health is deteriorating from fatigue.”/“The woman often complains that she fatigues easily.”；nightmare “梦魇”如：“In his nightmares they burned his house.”； relaxation 放松、休闲娱乐活动。