With Airbus’s giant A380 airliner about to take to the skies, you might think planes could not get much bigger and you would be right. For a given design, it turns (1) , there comes a point where the wings become too heavy to generate (2) lift to carry their own weight. (3) a new way of designing and making materials could (4) that problem. Two engineers (5) University College London have devised an innovative way to customise and control the (6) of a material throughout its three dimension al structure.
In the (7) of a wing, this would make possible a material that is dense, strong and load-bearing at one end, close to the fuselage, (8) the extremities could be made less dense, lighter and more (9) . It is like making bespoke materials, (10) you can customise the physical properties of every cubic millimetre of a structure.
The new technique combines existing technologies in a(n) (11) way. It starts by using finite-element-analysis software, of the type commonly used by engineers, (12) a virtual prototype of the object. The software models the stresses and strains that the object will need to (13) throughout its structure. Using this information it is then (14) to calculate the precise forces acting on millions of smaller subsections of the structure. (15) of these subsections is (16) treated as a separate object with its own set of forces acting on it--and each subsection (17) for a different microstructure to absorb those local forces.
Designing so many microstructures manually (18) be a huge task, so the researchers apply an optimisation program, called a genetic algorithm, (19) . This uses a process of randomisation and trial-and-error to search the vast number of possible microstructures to find the most (20) design for each subsection.

A:asks B:calls C:demands D:requires

More and more residences, businesses, and even government agencies are using telephone answering machines to take messages or give information or instructions. Sometimes these machines give (1) instructions, or play messages that are difficult to understand. If you (2) telephone calls, you need to be ready to respond if you get a (3) . The most common machine is the (4) used in residence. If you call a home (5) there is a telephone answering machine in operation you (6) hear several rings and then a recorded message (7) usually says something (8) this: "Hello. We can’t come to the (9) right now. If you want us to call you back, please leave your name and number after the beep." Then you will hear a "beep," (10) is a brief, high-pitched (11) . Alter the beep, you can say who you are, whom you want to speak to, and what number the person should call to (12) you, or you can leave a (13) . Some telephone answering machines (14) for only 20 or 30 seconds after the beep, so you must respond quickly. Some large businesses and government agencies are using telephone answering machines to provide information on (15) about which they receive a large volume of (16) . Using these systems (17) you to have a touch-tone phone (a phone with buttons rather than a rotary dial). The voice on the machine will tell your to push a certain button on your telephone if you want in-formation on Topic A, another button for Topic B, and so on. You listen (18) you hear the topic you want to learn about, and then you push the (19) button. After making your (20) , you will hear a recorded message on the topic.

A:commands B:requires C:asks D:requests

The fellow is very ______ . He never asks others for advice.

A:conceited B:proud C:thoughtful D:selfish

The police station asks for public help because ______.

A:ordinary people like the television programme B:ordinary people are interested in pictures of paintings, jewellery, etc. C:the policemen can not catch the thieves themselves D:ordinary people may help the policemen get useful information about the criminals

When the teacher asks a question, you should ______.

A:raise your hand B:give an answer C:repeat the question D:keep silence

John puts up his（）hand the teacher asks a question

A:every time   B:in time    C:some time     D:at times

My teacher always inspires me to do what I prefer.

A:teaches B:asks C:encourages D:insists

In "Speed Reading" courses, teachers often asks students to ______.