【单选题】Choose the best answer accoding to the recording. The Chinese don’t give clocks as presents because they think the clocks may have an implied meaning of ___________.
【单选题】The history of clocks is very long, and there have been many different types of clocks over the centuries. 1. __________________________________
A.
Dividing the day into hours, minutes,and seconds
C.
Dividing the year into months and days
【简答题】A.Bells and masks. B.Clocks and masks. C.Clocks and swords. D.Bells and swords.
【简答题】Their inner clocks tell them just where the sun will be, and they change their _____ correspondingly.
【简答题】从4名男生和2名女生中任选3人值日,设随机变量ξ表示所选3人中女生的人数. (Ⅰ)求ξ的分布列、数学期望Eξ; (Ⅱ)求事件“所选3人中女生至少有1人”的概率.
【单选题】What is the meaning of 'working round the clock'?
C.
Working with a clock nearby.
D.
Working day and night.
【单选题】(17.18题共用题干)患者,男,40岁,职业司机,间断上腹胀痛3年,常于餐后加重,冬春为重,3天前上腹胀痛加重,伴泛酸,嗳气。患者吸烟16年,平均20支/日,经胃镜检查,诊断为“胃溃疡”收入院。该患者饮食护理中,应尽量避免
【简答题】从5名女生和2名男生中任选3人参加英语演讲比赛,设随机变量ξ表示所选3人中男生的人数. (1)求ξ的分布列; (2)求ξ的数学期望; (3)求“所选3人中男生人数ξ≤1”的概率.