Anyone who has messy children, lazy partners or naughty flat mates will be impressed by the resourcefulness (足智多谋) of Katrina Neathey, the co-owner of a cleaning company in West Sussex. She has made her three teenagers sign an agreement to help keep the house tidy. Any infraction of the agreement, for example, littering up their bedroom with magazines and drinks, or failing to put their dirty plates in the dishwasher, will come with a 5 pounds' fine or removal of their phones.

It is one way of setting up a cleaning rota (轮班表) that people might stick to. “Cleaning is teamwork,” says Lynsey Crombie, also known as the Queen of Clean. She suggests getting everyone in the household together to find out what people like doing. “In our family, my husband is better at mowing the lawn. I love cleaning rooms. Someone else might like folding the towels. You let everybody do what they're good at, or enjoy, so there's more chance they'll actually do it.”

Crombie is not a fan of fines. For her children, she takes away their phones or turns off the Wi-Fi. For other adults who aren't joining in, she suggests keeping asking them to take action.

If you aren't sure what is required to keep the dirt at bay, there are many checklists online that you can print out to share the daily, weekly and monthly tasks. You can stick it on the fridge, and then everyone knows where they stand.   If it's not working, have another chat, such as “What do you dislike?” “How can we improve it?” Ironig out problems is all about communication.

Arjun's Apps

One stormy day, twelve-year-old Arjun Kumar was late getting home from school. It had been raining heavily near his school in Chennai, India. This delayed his school bus, and when he finally arrived, Arjun’s parents were worried.

His parents’ concern gave Arjun an idea — he’d create an app, which can tell parents the location of their children’s school bus. While researching different ways to write apps, Arjun located an online programming tool on the website of the Massachusetts Institute of Technology. MIT was making the tool, called App Inventor, available to anyone who wanted to use it. As the motto on MIT's website states, “Anyone Can Build Apps That Impact the World.”

Arjun got to work doing just that. Using App Inventor, he created an app called “Ez School Bus Locator.” If a school introduced this app into its bus system, parents could log on to see the locations and estimated arrival times of their children’s school bus. Like other mapping apps, Ez School Bus Locator relied on GPS. GPS helps users determine their location, based on signals from a set of twenty-four satellites that orbit Earth. GPS-based apps calculate the location of a device by measuring the distances from three different GPS satellites. That's how Arjun's app determined where the buses were located.

The app could also confirm whether individual children were on the bus. Ez School Bus Locator used a specific bar code to identify each student. Students checked in when they got on and off the bus by using bar codes on their phones. As the bus driver drove, the app sent automatic messages to parents.

Does Ez School Bus Locator sound like a good idea? MIT thought so. In 2012, MIT held a contest to honor the best apps that had been created using App Inventor. Arjun's app won first place in the K-8 division, and in 2013, the app was available for purchase online.

Arjun didn't stop there. He continued developing new apps and he even started his own software development company. When asked for pointers for other young inventors, Arjun advised, “Look for problems around you, and get inspired from them. You’ll see a lot of opportunities to use your skills to make this world a better place to live!”

Do you still remember Jurassic Park, an amazing movie where science brings dinosaurs back from extinction? Now some very smart scientists are working on a way to revive, not dinosaurs, but other extinct species like the woolly mammoth （长毛象）using the gene editing technology known as CRISPR.

As an evolutionary biologist, obviously, it would be amazing to bring back extinct creatures. But even if we can bring them back, we are not going to be able to control how they evolve in the future. No man is an island and neither is any other creature. We need an ecosystem in order to survive. So we can think a lot about the examples of reintroducing species into the environment, like the gray wolves into Yellowstone. Ecology is very complicated and it certainly wasn't important when we first introduce rabbits into Australia, which was a total disaster eventually.

All animals like birds and mammals have to learn from their parents. If we bring them back to life, who are going to be around to teach them? We have examples where in California we've had the reproduction of the condors （秃鹰）.What scientists tried to do is to feed the babies using a mother condor puppet. When these poor creatures were released into the wild, they had an unnatural liking for humans. They didn't behave the way they should have, for condors.

According to Performing Animal Welfare Society, a healthy elephant costs about $70,000 per year to care for and an elderly elephant costs a good deal more. Of course, we are not talking about one. We're talking about many creatures. I don't think these creatures will have a future.