研究生入学 2022_03_29 每日一练

设P=

,Q为三阶非零矩阵,且PQ=O,则().

A.当t=6时,r(Q)=1
B.当t=6时,r(Q)=2
C.当t≠6时,r(Q)=1
D.当t≠6时,r(Q)=2

下列关于术后患者的饮食处理，错误的是
A.非腹部局麻下的手术，术后即可进食
B..非腹部腰麻或硬膜外麻醉下的手术，一般术后2 ~3天即可进食
C.非腹部全麻下的手术，患者清醒，无呕吐时可进食
D.择期胃肠道手术,肠蠕动恢复后,可开始饮水，进少量流食
E.腹部手术需禁食时间较长者，应给予胃肠外营养

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Text 3 The hotel guestroom telephone is being ignored more and more these days.The average hotel guest checks in with three mobile devices.That has pushed the guestroom phone down the list of preferred communication devices,"We have noticed a signiflcant decline in guestroom phone usage and that guests,by and large,bring and use their own mobile phones:'says Kevin Carl,executive vice president of Radisson Hotel Group.And why not?Hotels traditionally have charged exorbitant（过高的）prices for the privilege of using a landline.Travelers are now hanging up on the traditional phone and using the hotel room phone only for minor logistical purposes,thanks to the advent of new technologies.Kate Ashton,senior vice president of operations for Wyndham Grand,says the most common uses for in-room phones are for calls to the front desk.The most frequently asked questions are"What's the Wi-Fi password?"and"When is checkout time?"That said,hotels say they would never give up on Iandlines for the simple reason that they need them for security."Having a landline accessible means guests can always have a way to call in case of emergency or if they have any issues with their own devices,"Ashton says.That doesn't mean the guestroom telephone is not changing or that hotels aren't finding technologies to supplement the landline."Telephones continue to evolve and become more stylish in the hotel space,"says Andrea Torrance,vice president of operations for AccorHotels North and Central America.Hotel room phones used to be quite simple with one line and basic services.Now companies such as Cetis provide extensive services out of one device such as one-touch voice mail retrieval,Bluetooth paring for music streaming and digital clocks.They also have built-in USB charging ports for smarfphones."Now,the trend seems to be going backward in time to a single line corded telephone,"says Chad Collins,vice president of sales for the Americas at VTech,a company that produces hotel landlines."I believe this is driven by the fact that hotels simply want a telephone with a dial tone,not all of the bells and whistles.Guests'demands are changing,and the telephone is not excluded from those changes."But many hotels are finding other ways to communicate with guests.Roxy,a Seattle start-up,has created speech-enabled devices that will allow hotels to replace landlines with voice-activated calling.The devices also act as a guests'personal concierge.Guests can place requests to the front desk and get recommendations for restaurants and activities.Collins says there is no way a landline will compete with a mobile phone.But he believes both can serve different purposes."The idea that we are trying to compete with mobile devices is a bit misguided,"he says.32.Hotels insist on the use oflandlines for

A.customer consultation.
B.emergency use.
C.logistical purposes.
D.better reputation.

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人力资本理论认为，人力资本是经济增长的关键，教育是形成人力资本的重要力量。这一理论的主要缺陷是

A.忽视了教育的其他社会功能
B.有教育万能论的倾向
C.忽视了劳动力市场中的其他筛选标准
D.夸大了教育对人力资本的作用

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邓小平为什么把解放和发展生产力纳入社会主义本质之中?

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痰浊头痛的临床特征是

A.头痛而眩
B.头痛而空
C.头痛如裹
D.头痛昏蒙眩晕

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已知10件产品中有4件一等品，从中任取2件，则至少有1件一等品的概率为