下列物质不属于混合物的是 [ ] A. 空气 B. 矿泉水 C. 液氧 D. 石

题型:选择题

问题:

下列物质不属于混合物的是 [ ]

A. 空气

B. 矿泉水

C. 液氧

D. 石灰石

考点:单质和化合物
题型:选择题

实验室用过氧化氢和二氧化锰来制取和收集氧气用到的一组仪器是(  )

A.集气瓶、导管、胶头滴管、药匙

B.漏斗、量筒、铁架台、集气瓶

C.铁架台、试管、导管、集气瓶

D.试管、酒精灯、铁架台、集气瓶

题型:选择题

以下叙述中不正确的是

A.一个类的友元函数可以无条件的使用这个类的私有成员

B.静态成员函数可以直接访问非静态数据成员

C.不可以声明抽象类的对象,但可以声明抽象类的指针变量

D.静态数据成员为类的所有对象所共有

题型:选择题

如何判断硫回收催化剂失活()。

A.转化器出口温度高

B.床温低

C.温升低,转化器出入口分析无变化

D.温升高,转化器出入口分析有变化

题型:选择题

堆载预压荷载分级的原因是( )。

A.受工期的影响

B.受总荷载大小的影响

C.受地基土性质的影响

D.受建筑物要求的影响

题型:选择题

Visitors to Britain may find the best place to sample local culture is in a traditional pub. But these friendly hostelries can be minefields of potential gaffes for the uninitiated.
An anthropologist and a team of researchers have (1) some of the arcane rituals of British pubs—starting with the (2) of getting a drink. Most pubs have no waiters—you (3) to go to the bar to buy drinks. A group of Italian youths (4) for 45 minutes before they realized they would have to (5) for their own. This may sound inconvenient, but there is a (6) purpose.
Pub culture is designed to (7) sociability in a society known for its reserve. Standing at the (8) for service allows you to chat with others (9) to be served. The bar counter is possibly the only (10) in the British Isles in which friendly conversation with (11) is considered entirely appropriate and really quite normal (12) . "If you haven’t been to a pub, you (13) been to Britain." This tip can be found in a (14) , Passport to the Pub: The Tourists’ Guide to Pub Etiquette, a (15) code of conduct for those wanting to sample "a central part of (16) life and culture". The trouble is that if you do not (17) the local rules, the experience may fall flat. For (18) , if you are in a big group, it is best if only one (19) two people go to buy the drinks. Nothing irritates the (20) customers and bar staff more than a gang of strangers blocking all access to the bar while they chat and dither about what to order.

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