关系数据库设计理论是数据库逻辑设计的指南，其主要基础是______和______。

下列句子中没有错别字的是 [ ]

A．这里盛产优质雪花梨，可以就地取才办一个水果加工厂。

B．当遇到重大问题需要他拿主意的时候，他反倒迟疑不绝了。

C．今年春节期间，各地电视台的文艺节目多得令人目不暇接。

D．北京办奥运，既展示传统文化又展现精神风貌，可谓两全齐美。

☆Locks

You have a special card which operates the electronic lock on your room door and a key for the main door of the door of the hotel. These are your responsibility and should never be lent to anyone, including your fellow classmates. If you lose them you will be charged £20 per replacement. Do not leave your room unlocked even for short periods. Unfortunately, theft from student hotels is very common and insurance companies will not pay for stolen goods unless you can prove that your room was broken into by force.

☆Visitors

There are rarely any rooms available for visitors, except at the end of the summer term. Stan Jenkins, the hotel manager, will be able to tell you and can handle the booking. A small charge is made. Stan also keeps a list of local guesthouses, with some information about what they’re like, price, etc. You are also allowed to use empty beds for up to three nights, with the owner’s permission (for example, if the person who shares your room is away for the weekend ), but you must inform Stan before your guest arrives, so that he has an exact record of who’s in the building of a fire breaks out. Students are not allowed to charge each other for this.

☆Kitchens

There is a kitchen on each floor where light meals, drinks, etc. maybe prepared. Each has a large fridge and a food cupboard. All food should be stored, clearly marked with the owner’s name, in one of these two places. Bedrooms are too warm for food to be stored, and the cleaners have instructions to remove any food found in them. After using the kitchen, please be sure you do all your washing up immediately and leave it tidy. If you use it late in the evening， please also take care that you do so quietly in order to avoid disturbing people in nearby bedrooms.

小题1:If a friend visits you for the weekend, he or she can        .

A．stay at a local guesthouse

B．book an empty house for free

C．use an empty bed without permission

D．share your room by paying your roommate小题2:Which of the following is true according to the passage?

A．Your insurance will cover what you have lost．

B．The cleaners will take away food left in the bedrooms．

C．Spare rooms are least likely to be available in summer．

D．Students will be fined for lending their cards to others．小题3:The passage is probably taken from ____．

A．a travel guide book

B．a hotel brochure

C．a school poster

D．a club newsletter

新生儿颅内压增高重要的体征是()

A．瞳孔不等大

B．巴宾斯基征阳性

C．呼吸不规则

D．脑膜刺激征阳性

E．前囟隆起

下列物质中，只含有非极性共价键的是[ ]

A.NaOH

B.NaCl

C.H₂

D.H₂S

压缩机密封油高位槽具有（）作用。

A.增加密封油压力

B.当密封油泵出现故障时，能维持密封油一定压力，防止工艺气窜出

C.缓冲作用，减小密封油压力的波动

D.以上都不是