[单项选择]After the violent earthquake that shook Los Angeles in 1994, earthquake scientists had good news to report: the damage and death toll could have been much worse. 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 aren’’t 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
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