More than 60 people died in this earthquake. By comparison, an earthquake of similar intensity that shook America in 1988 claimed 25, 000 victims.
Injuries and deaths were relatively less in Los Angeles because the quake occurred at 4:31 a.m. on a holiday, when traffic was light on the city's highways. In addition, changes made to the construction codes in Los Angeles during the last 20 years have strengthened the city's buildings and highways, making them more resistant to quakes.
Despite the good news, civil engineers are not resting on their successes. Pinned to their drawing boards are blueprints for improved quake-resistant buildings. The new designs should offer even greater security to cities where earthquakes often take place.
In the past, making structures quake-resistant meant firm yet flexible materials, such as steel and wood, that bend without breaking. Later, people tried to lift a building off its foundation, and insert rubber and steel between the building and its foundation to reduce the impact of ground vibrations. The most recent designs give buildings brains as well as concrete and steel supports, called smart buildings. The structures respond like living organisms to an earthquake's vibrations. When the ground shakes and the building tips forward, the computer would force the building to shift in the opposite direction.
The new smart structures could be very expensive to build. However, they would save many lives and would be less likely to be damaged during earthquakes.
One reason why the loss of lives in the Los Angeles earthquake was comparatively low is that ______.
A.new computers had been installed in the buildings
B.it occurred in the residential areas rather than on the highways
C.large numbers of Los Angeles residents had gone for a holiday
D.improvements had been made in the construction of buildings and highways
第2题
创建报表的命令是()。
A.CREATE REPORT
B.MODIFY REPORT
C.RENAME REPORT
D.DELETE REPORT
第3题
创建索引的命令是()。
A.Create trigger
B.Create procedure
C.Create Function
D.Create index
第4题
创建视图命令是()。
A.CREATE VIEW
B.DROP VIEW
C.CREATE TABLE
D.CREATE RULE
第5题
在SQL中,创建基本表用______。
A.CREATE SCHEMA命令
B.CREATE TABLE命令
C.CREATE INDEX命令
D.CREATE VIEW命令
第7题
创建数据库的命令为()。
A.Create database
B.alter database
C.use database
D.drop database
第8题
在Visual FoxPro中,创建一个名为Sdb.dbc的数据库文件,使用的命令是( )。
A.CREATE B.CREATE Sdb
C.CREATE TABLE Sdb D.CREATE DATABASE Sdb
第9题
在SQL中,创建基本表用
A.CREATE SCHEMA命令
B.CREATE TABLE命令
C.CREATE INDEX命令
D.CREATE VIEW命令
第10题
下列与创建表结构相关的命令是()。
A.CREATE
B.ALTER
C.UPDATE
D.INSERT
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