填空题 Directions: In this section, you will hear a passage three times. When the passage is read for the first time, you should listen carefully for its general idea. When the passage is read for the second time, you are required to fill in the blanks numbered from 36 to 43 with the exact words you have just heard. For blanks numbered from 44 to 46 .you are required to fill in the missing information. For these blanks, you can either use the exact words you have just heard or write down the main points in your own words. Finally, when the passage is read for the third time, you should check what you have written.
The National Weather Service is revamping the way it has issued severe weather warnings for decades with a new system designed to mark a geographic bull's eye where a storm will hit.
The system, which goes into effect on Oct. 1, {{U}} {{U}} 1 {{/U}} {{/U}}from alerts based on county lines to notices aimed at {{U}} {{U}} 2 {{/U}} {{/U}}communities, weather service officials said Tuesday. Using radar and computer {{U}} {{U}} 3 {{/U}} {{/U}}programs, the system is meant to predict the moment a storm will hit a community or even a {{U}} {{U}} 4 {{/U}} {{/U}}crossroads.
Known as storm-based warnings, the new alerts could {{U}} {{U}} 5 {{/U}} {{/U}}a warning area from thousands of square miles to a few hunched square miles, experts said.
"A storm-based warning {{U}} {{U}} 6 {{/U}} {{/U}}on a storm itself and the geographic area that might be affected by it, " said Eli Jacks, a meteorologist at NWS {{U}} {{U}} 7 {{/U}} {{/U}}in suburban Washington.
The new system will {{U}} {{U}} 8 {{/U}} {{/U}}be limited to warnings for tornadoes, severe thunderstorms, floods and marine hazards. Later, it will be expanded to include other threats like extreme heat, Jacks said.
Tornado forecasting began in the late 1940s, and {{U}} {{U}} 9 {{/U}} {{/U}}Warnings generally have been issued on a county-by-county basis ever since.
Under the new system, {{U}} {{U}} 10 {{/U}} {{/U}}On a radar map, the wamed areas appear as highlighted polygons rather than entire counties; forecasters will refer to commonly known landmarks like rivers and roads in written announcements.
{{U}} {{U}} 11 {{/U}} {{/U}}