4 . The Yawa technology is an example of best practice in the circular economy. Materials used to build the machine are recyclable. The technology is even being adjusted to local air quality, a response to the challenges caused by air pollution. But most importantly, the technology can be used, owned and repaired by the communities it serves, even if they are not clear on the science behind it.

“When I was first testing this technology in different rural communities, I spent a lot of time explaining the technical aspects of it,” Hidalgo said. “At one point a woman stopped me and looked me in the eye and said, ‘Young man, I just want water.’ And that changed something inside of me, and I knew that I had to keep things simple.”

Hidalgo finds that getting out of the lab and into communities is vital for anyone seeking to produce environmental change. “We have to listen to what communities want and respond to their needs. That is where the winds of creation take us.” he said.

8 . Measles (麻疹), which once killed 450 children each year and disabled even more, was nearly wiped out in the United States 14 years ago by the universal use of the MMR vaccine (疫苗). But the disease is making a comeback, caused by a growing anti-vaccine movement and misinformation that is spreading quickly. Already this year, 115 measles cases have been reported in the USA, compared with 189 for all of last year.

The numbers might sound small, but they are the leading edge of a dangerous trend. When vaccination rates are very high, as they still are in the nation as a whole, everyone is protected. This is called “herd immunity”, which protects the people who get hurt easily, including those who can't be vaccinated for medical reasons, babies too young to get vaccinated and people on whom the vaccine doesn't work.

But herd immunity works only when nearly the whole herd joins in. When some refuse vaccination and seek a free ride, immunity breaks down and everyone is in even bigger danger.

That's exactly what is happening in small neighborhoods around the country from Orange County, California, where 22 measles cases were reported this month, to Brooklyn, N.Y., where a 17-year-old caused an outbreak last year.

The resistance to vaccine has continued for decades, and it is driven by a real but very small risk. Those who refuse to take that risk selfishly make others suffer.

Making things worse are state laws that make it too easy to opt out (决定不参加) of what are supposed to be required vaccines for all children entering kindergarten. Seventeen states allow parents to get an exemption(豁免), sometimes just by signing a paper saying they personally object to a vaccine.

Now, several states are moving to tighten laws by adding new regulations for opting out. But no one does enough to limit exemptions.

Parents ought to be able to opt out only for limited medical or religious reasons. But personal opinions? Not good enough. Everyone enjoys the life-saving benefits vaccines provide, but they'll exist only as long as everyone shares in the risks.

9 . Teens and younger children are reading a lot less for fun, according to a Common Sense Media report published Monday.

While the decline over the past decade is steep for teen readers, some data in the report shows that reading remains a big part of many children's lives, and indicates how parents might help encourage more reading.

According to the report's key findings, “the proportion (比例) who say they ‘hardly ever' read for fun has gone from 8 percent of 13-year-olds and 9 percent of 17-year-olds in 1984 to 22 percent and 27 percent respectively today.”

The report data shows that pleasure reading levels for younger children, ages 2—8, remain largely the same. But the amount of time spent in reading each session has declined, from closer to an hour or more to closer to a half hour per session.

When it comes to technology and reading, the report does little to counsel(建议) parents looking for data about the effect of e-readers and tablets on reading. It does point out that many parents still limit electronic reading, mainly due to concerns about increased screen time.

The most hopeful data shared in the report shows clear evidence of parents serving as examples and important guides for their kids when it comes to reading. Data shows that kids and teens who do read frequently, compared to infrequent readers, have more books in the home, more books purchased for them, parents who read more often, and parents who set aside time for them to read.

As the end of school approaches, and school vacation reading lists loom(逼近) ahead, parents might take this chance to step in and make their own summer reading list and plan a family trip to the library or bookstore.