4. Why did Mark Twain get so angry?

    A. Because the conductor had put someone else off the train.

    B. Because the conductor had forgotten to put him off in Paris.

    C. Because the conductor had forgotten to wake him up at Dijon.

    D. Because Mark Twain had not had enough sleep.      (DACC)

O

For a long time people who fish have had to rely on luck to catch fish. Even big fishing ships, fitted with radar and modern equipment, have their share of bad days. Wouldn't it be nice if fish could be trained to come at the call of a whistle the way some dogs do?

   Well, the days of "fish whistle" may be just around the corner. Japanese companies are working methods that will train fish to return to harvest areas at the sound of an underwater whistle.

   The method works like this: First, fish eggs are hatched in a laboratory. Whenever feeding time arrives, a whistle sounds. The young fish learn to return to their feeding areas at the sound of whistle.

   Later, the fish are released(放出) at sea, near specially-made underwater barns(仓库).There, the whistle-plus-feeding program continues.

Being well fed and sheltered(保护),the fish continue to "hang out" and around the "barn". So when fishing time arrives, all the harvesters need to do is to sound the whistle, drop their nets, and haul up a load of fish.

   Many countries have closed their offshore fishing waters to ship from other nations. With fish whistles and barns, Japanese hopes to become less dependent on(依赖) importing fish from other countries.

 0  293850  293858  293864  293868  293874  293876  293880  293886  293888  293894  293900  293904  293906  293910  293916  293918  293924  293928  293930  293934  293936  293940  293942  293944  293945  293946  293948  293949  293950  293952  293954  293958  293960  293964  293966  293970  293976  293978  293984  293988  293990  293994  294000  294006  294008  294014  294018  294020  294026  294030  294036  294044  447348 

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网