The most urgent thing is to find a dump for those toxic industrial wastes.A.imminentB.recy
The most urgent thing is to find a dump for those toxic industrial wastes.
A.imminent
B.recyclable
C.smelly
D.poisonous
The most urgent thing is to find a dump for those toxic industrial wastes.
A.imminent
B.recyclable
C.smelly
D.poisonous
第1题
A.likely
B.critical
C.emergent
D.urgent
第2题
A.it will be there temporarily
B.it's the most important expo work
C.it's not real and will vanish in the thin air
D.it's near Geneva
第3题
It must have taken a great prehistoric thinker to imagine two thin slices of log connected, at their centers by a string stick, this would roll along just as the logs did, yet be much lighter and easier to handle, thus the wheel and axle came into being and with them the first cart.
The wheel is important because ______ .
A.it was man' s first real invention
B.all transportation depends on it
C.every machine depends on it
D.both B and C
第4题
People in different parts of the world also have different ideas about what is good to drink. Among the most popular hot drinks are coffee and tea. Coffee is very popular in northern Europe and in the Middle East. Some people put cream and sugar in their coffee. But in the United States, many people drink their coffee "black" that is without cream or sugar. Tea is the national drink in China, Japan, and other Oriental(东方的) countries. In the Orient, people drink tea without sugar. But in England where it is also a national drink, many people use both sugar and hot or cold milk in their tea.
People in different parts of the world______.
A.cook the same food in different ways
B.like the same kinds of food
C.have the same ideas about foods
D.know how to prepare the same food
第5题
The process described by John Rogers and his colleagues from Bell Laboratories, an arm of Lucent Technologies, in New Jersey, and E Ink Corporation, in Cambridge, Massachusetts, starts with E Ink's established half-way house towards true electronic paper. This is based on spheres containing black, liquid dye and particles of white, solid pigment. The pigment particles are negatively charged, so they can be pushed and pulled around by electrodes located above and below the sheet.
The electrodes, in turn, are controlled by transistors under the sheet. Each transistor manipulates a single picture element (pixel), making it black or white. The pattern of pixels, in turn, makes up the picture or text on the page. The problem lies in making the transistors and connections. Established ways of doing this, such as photolithography, use silicon as the semiconductor in the transistors. That is all right for applications suck as pesters. It is too fragile and too expensive, though, for genuine electronic paper—which is why cheap and flexible electronic components are needed.
For flexibility, Dr. Rogers and his colleagues chose pentacene as their semiconductor, and gold as their wiring. Pentacene is a polymer whose semiconducting properties were discovered only recently. Gold is the most malleable metal known, and one of the best electrical conductors. Although it is pricey, so little is needed that the cost per article is tiny.
To make their electronic paper the researchers started with a thin sheet of Mylar, a tough plastic, that was coated with indium-tin oxide (ITO), a transparent electrical conductor. To carve this conductor into a suitable electric circuit, they used an innovation called microcontact printing lithography. This trick involves printing the pattern of the circuit on to the ITO using a rubber stamp. The "ink" in the process is a solvent-resistant chemical that protects this part of the ITO while allowing the rest to be dissolved.
From the first paragraph of the passage, we can learn that an electronic display ______.
A.can be made as good as paper
B.is cheap enough to be pasted on to walls and billboards
C.will be as thin and flexible as paper
D.is difficult to be created in the form. of flexible electronic circuitry
第6题
One of the most interesting new uses for glass is in telephone communication. Scientists have developed glass fibers as thin as human hair, which are designed to can-y light signals. When the light reaches the other end, it is first changed into electrical signals, which are in turn converted into sound messages.
Called light wave communication, the new system was used successfully in an experiment in Chicago in 1997. During the experiment, two glass fibers were able to carry 672 conversations at the same time. The lightwave cable, containing 144 glass fibers, has the capacity to carry 50,000 conversations at the same time.
The lightwave communication system has two important advantages. First, the glass fiber cables are smaller and weigh less than copper. Second, they cost less.
Perhaps it can be said that telephone communication has entered the age of light.
One of the extraordinary qualities of glass is that it can carry ______.
A.sound signals
B.light signals
C.electrical signals
D.any signals
第7题
According to the writer, the main problem to our environment today is______.
A.the increase of population
B.the limited energy resources
C.the more serious air pollution
D.the development of technology
第10题
The newly built factory is in urgent need of a number of skilled and ______ workers.
A.consistent
B.conscious
C.confidential
D.conscientious