保险产生的物质基础是（）。 A.风险 B.剩余产品 C.社会分工 D.商品交换

在定义类的对象时，C++程序将自动调用该对象的 【11】 函数初始化对象自身。

Pupils remember more and behave better when 3D images are used in lessons，research suggests．They are quicker to learn and absorb new concepts，and display higher levels of concentration．

Professor Anne Bamford，of the University of the Arts，London， studied the effectiveness of 3D content in 15 schools across seven countries，including the UK．Pupils in 3D classes can remember more than those in the 2D classes after four weeks，improving test scores by an average of 1 7 percent compared with eight percent for 2D lessons．They gave more detailed answer to the tasks and were more likely to think in 3D, using hand gestures and mime(模仿动作) to answer the test questions successfully．

The teachers commented that the pupils in the 3D groups had deeper understanding，increased attention span．more motivation and higher engagement in the lessons．

Children are used to 3D with the rise of computer games that use the technology—90 percent of those in the study had seen a 3D film．Schools would need 3D—enabled projectors(投影仪)，laptops with good picture capabilities，3D software and glasses for children to introduce animations(动作) into classrooms．

But Danny Nicholson，an educationist，said the technology would be impractical to use in schools and could be costly．He said，“While I think the idea of 3D technology is very interesting， I worry that 3D is a bit of an expensive gimmick(小玩意儿)．There are a few cases where a true 3D image might help，but most of the time，good 2D models that can be moved would be just as effective．”

In the US，one school district in Colorado is already in the process of having 1．000 3D projectors fixed in classrooms．And the University of Caledonia．which carries out scientific research into the Lake Tabon Basin．has used 3D presentations with Grade Six pupils．Those who watched the 3D presentations were more engrossed and reported a general increase in their interest in science compared with students who watched the 2D version．

小题1:What is the main idea of the first three paragraphs?

A．There are slight differences between 3D and 2D images．

B．Pupils perform better when 3D images are used in classes．

C．Schools have difficulties in making full use of 3D technology．

D．3D technology is always more effective than 2D technology．小题2:Danny Nicholson holds the view that 3D_____.

A．is of no help in classes

B．has a bright future in classes

C．is more practical than 2D models

D．may not be affordable for schools小题3:What can we learn from the last paragraph?

A．3D technology will replace 2D models in the future．

B．Many pupils are now more Interested In science than before．

C．Teachers will use the 3D technology through specific training．

D．3D will soon be put into use in one school district in Colorado．小题4:The underlined word “engrossed” in the last paragraph means_____.

A．absorbed

B．annoyed

C．relaxed

D．confused

台钻的最低转速较高时，不适用于锪孔和铰孔。

联合国环境组织派人来你市考察环境污染情况，由你向他们介绍：学校位于一个山脚下，一条小河从旁边流过。两年前，学校南面建起一座化工厂，排出大量废气、废水，造成严重污染，影响师生健康。如今政府采取了一系列保护环境、防止污染的措施，现在学校美如花园，校园内树木四季常青，鲜花争艳。

1. 文章必须包括以上介绍的主要内容，可以适当增减细节，使内容连贯；

2. 词数：100—120；

3. 参考词汇：poisonous 有毒的

下列急性胆道感染常见的严重并发症中，应排除

A．急性坏死性胰腺炎
B．硬化性胆管炎
C．胆道出血
D．感染性休克
E．肝脓肿