If you are writing or studying, it makes very much difference where the light comes from. People who use books and pens every day (1) to be especially careful about the direction from which the light shines on their work.A house gets it’s light (2) from daylight through windows (3) is very good to use or from the lamps, but no matter what kind of light it is, the direction it slants(倾斜) towards our books or our work is a matter of great (4) to the eyes.

Take a book,stand with your back toward the window, and try to read. Your shadow falls across the page and makes it bad for your eyes as if you were in a (5) room.

Now turn (4) and face the window. The page is the shadow again,while the bright light is in your (7) . Try standing with your right side towards the window. This is very good for reading, (8) if you were writing,the shadow would (9) the page and trouble you a little.

There is just one other way: stand with your (10) side to the window. Now everything is perfect for reading and for writing, too.

Advances in computers and data networks inspire visions of a future "information economy" in which everyone will have (1) to gigabytes of all kinds of information anywhere and anytime, (2) information has always been a (3) difficult commodity to deal with, and, in some ways, computers and high-speed networks make the problems of buying, (4) , and distributing information goods worse (5) better. The evolution of the Internet itself (6) serious problems. (7) the Intemet has been privatized, several companies are (8) to provide the backbones that will carry traffic (9) local networks, but (10) business models for intereonnectinn—who pays how much for each packet (11) , for example—have (12) to be developed. (13) intereonnection standards are developed that make (14) cheap and easy to transmit information across independent networks, competition will (15) . If technical or economic (16) make interconnection difficult, (17) transmitting data across multiple networks is expensive or too slow, the (18) suppliers can offer a signfficant performance (19) ; they may be able to use this edge to drive out competitors and (20) the market.

Now is a good time to start playing.

They had better see who is winning.

The game began some time ago.

正确

错误

This afternoon.

Tomorrow afternoon.

Tomorrow.