【米国】街灯をLEDに替えたら夜の暴力犯罪が46%減。でも効果は半年で消えた

Q1. What is the passage mainly about?

1. AHow to make LED lights at home
2. BNew streetlights and crime in one city
3. CWhy people in Newark go out at night
4. DHow workers fix old cars

第2〜4文で、ニューアーク市で街灯をLEDに替え、その近くの犯罪を数えた話をしているので、正解は B。

Q2. How long did the big drop in violent crime last?

1. AAbout six months
2. BAbout two years
3. CAbout 46 days
4. DIt is still going on

「For the first six months, there was much less violent crime」とあり、その後「the change went away」なので、正解は A（約6か月）。46は減った割合、2年は調べた期間。

Q3. In the passage, "went away" means the change ___.

1. Abecame bigger
2. Bmoved to another city
3. Cdisappeared
4. Dstarted again

go away は「消える・なくなる」。直後に「Over the full two years, there was no clear difference（2年間全体で見ると、はっきりした差はなかった）」とあるので、正解は C。

Q1. What is the passage mainly about?

1. AA study of how new streetlights affected crime over time
2. BA plan to sell LED lamps to other cities
3. CWhy sodium lights use too much power
4. DHow police in Newark catch criminals

街灯をLEDに替えたあと、犯罪の数が最初の6か月とその後でどう変わったかを調べた研究の話なので、正解は A。

Q2. What did the researchers compare the crime numbers with?

1. ACrime numbers in New York City
2. BCrime numbers from the 1990s
3. CCrime numbers around poles that were not changed
4. DCrime numbers inside the power company

「compared these numbers with the numbers around poles that were not changed, a few blocks away」とあるので、正解は C。

Q3. Which statement would the writer most likely agree with?

1. ANew LED lights stopped violent crime for good.
2. BThe new lights had a strong effect at first, but it did not last.
3. CThe new lights made violent crime much worse in the first year.
4. DStreetlights have nothing to do with crime.

最初の6か月は約46%少なかったが、「After half a year, the difference disappeared」とあるので、正解は B。ずっと止めたわけでも、最初の年に増えたわけでもない。

Q1. What is the passage mainly about?

1. AWhy LED lights are cheaper than sodium lights
2. BA study showing that brighter streetlights cut violent crime only for a short time in one city
3. CHow corner stores in Newark became safer
4. DA plan to install LED lights in New York City public housing

ニューアークで街灯をLEDに替えると最初の半年は暴力犯罪が約46%少なかったが、「After six months, though, the gap closed」と効果が続かなかった研究の話なので、正解は B。

Q2. Why did the researchers use a quasi-experimental design?

1. ABecause the poles were not chosen at random
2. BBecause the police did not keep any records
3. CBecause the study lasted only six months
4. DBecause the lights were installed in New York City

「Because the poles were not chosen at random, researchers ... used a quasi-experimental design」とあるので、正解は A。

Q3. Why does the writer mention the trial in New York City?

1. ATo prove that streetlights never work
2. BTo show that Newark copied New York's plan
3. CTo suggest that the effect of lighting may differ from place to place
4. DTo explain how LED fixtures are made

ニューヨークでは3年分のデータで見ても効果が続いたと紹介し、「the results seem to depend heavily on the setting」と続けているので、正解は C。