3 . Could your dog be prone to a fatal disease? Is your new shelter pup part beagle or boxer? Many pet owners seek answers to these questions, and as a result, direct-to-consumer dog DNA testing is booming.

Human interfering with dog DNA has long been the driving factor behind dogs’ breed diversity — or lack thereof. But a dog’s DNA can also be used to confirm their lineage (血统) or identify their breed, a boon for pet owners on the lookout for breed-specific health or behavioral challenges or those looking to confirm their dog really has the heritage claimed by a breeder or seller. During DNA analysis, labs sequence the dog’s DNA and look for similarities with a dataset of identified dog breeds.

But breed identification isn’t as simple as it might seem. In a study published in the Journal of the American Veterinary Medical Association last month, scientists looked into the accuracy of breed prediction in commercially available DNA tests that required a photo of the dog in addition to its DNA sample. The results were mixed, says Casey Greene, a professor who co-authored the study.

“Most tests could accurately distinguish the breed of purebred dogs,” says Greene. But the analysis suggested that some testing companies might rely on the photo more than the dog’s actual genetics — and revealed big differences between companies’ business practices and the genetic datasets they use to determine dog breeds.

The researchers submitted photos and DNA of 12 purebred dogs to a total of six commercial canine (犬的) ancestry identification services. Since each pup was purebred and possessed extensive American Kennel Club paperwork, the researchers knew their breed conclusively—but in some cases they provided a photo of a different dog to see if the photo influenced the DNA results. One of the companies misidentified a purebred Chinese crested dog — almost entirely hairless — as a long-haired Brittany spaniel, seemingly based on the photo alone. The other five did identify the registered breed correctly, but often gave different predictions for other “ancestor” breeds in dogs whose DNA suggested mixed breeding in prior generations. The researchers concluded that veterinarians and pet owners alike should “approach direct-to-consumer tests with caution” given the lack of industry standardization and at least one company’s reliance on photographs instead of DNA analysis.

Despite these concerns, though. dog DNA seems headed for a golden age — and the insights revealed through further study of Fido’s genome (基因组) have already reached far beyond the doghouse. Domesticated dogs have emerged as surprising superstars in medical research that benefits humans. According to researchers, that’s just the beginning. With implications ranging from entertaining to consequential, there’s no telling what dog DNA will continue to unleash.

6 . Maps, number lines, shapes, artwork and other materials tend to cover elementary classroom walls. However, too much of a good thing may end up _______ attention and learning in young children, according to research published in Psychological Science.

Psychology researchers Anna V. Fisher, Karrie E. Godwin and Howard Seltman of Carnegie Mellon University looked at whether classroom displays affected children’s ability to maintain _______ during instruction and to learn the lesson content. They found that children in highly decorated classrooms were more distracted, spent more time off-task and demonstrated smaller learning _______than when the decorations were removed.

“Young children spend a lot of time — usually the whole day — in the same classroom, and we have shown that a classroom’s _______ environment can affect how much children learn,” said Fisher, lead author and associate professor of psychology in the Dietrich College of Humanities and Social Sciences.

Should teachers _______ their visual displays based on the findings of this study?

“We do not suggest by any means that this is the answer to all _______ problems. Furthermore,_______ research is needed to know what effect the classroom visual environment has on children’s attention and learning in real classrooms,” Fisher said. “_______, I would suggest that instead of removing all decorations, teachers should consider whether some of their visual displays do make it difficult for young children to _______.”

For the study, 24 kindergarten students were placed in ________classrooms for six introductory science lessons on topics they were unfamiliar with. Three lessons were taught in a heavily decorated classroom, and three lessons were given in a sparse (稀疏的) classroom. The results showed that while children learned in both __________ types, they learned more when the room was not heavily decorated. Specifically, children’s __________ on the test questions was higher in the sparse classroom (55% correct) than in the decorated classroom (42% correct).

“We were also interested in finding out if the visual displays were removed, whether the children’s attention would __________ to another distraction, such as talking to their peers, or the total amount of time they were distracted would remain the same,” said Godwin, a Ph.D. candidate in psychology and fellow of the Program in Interdisciplinary Education Research.

However, when the researchers totaled all of the time children spent off-task in both types of classrooms, the rate of off-task __________ was higher in the decorated classroom (38.6% time spent off-task) than in the sparse classroom (28.4% time spent off-task).

The researchers hope these findings will lead to further studies into developing guidelines to help teachers design classrooms __________.

10 . In Favour of Simple Writing

Do you edit text messages carefully before sending them? If so, you may be the kind of person who takes pride in _______ even the simplest message. If you do not, you may see yourself as a go-getter, one who values excitement and speed over _______: get it done decently now rather than perfectly later.

People are constantly receiving messages, from the mailbox to the inbox to the text-message alert. What to read, what to skim (略读) and what to ignore are decisions that nearly everyone has to make dozens of times a day. A new book titled All Readers are Busy Nowadays makes the argument for being the careful kind of _______, even in informal lines. The authors also present well-established _______ that have long been prized in guides to writing.

Take “less is more”. Most books on writing well advocate the advice to _______ needless words. The authors, however, have _______ the idea. In an email to thousands of school-board members asking them to take a survey, cutting the count from127 to 49 words almost _______ the response rate.

Keeping messages to a _______ idea—or as few as absolutely needed—helps ensure that they will be read, remembered and acted on. _______ the number of the available options has the same effect, too. A link in an email, ________, attracted 50% more clicks when presented alone than when it was sent alongside a second additional link.

Syntax (句法) and ________ matter, too. It is more ________ to adopt short and active sentences, with common words familiar to everyone. From Facebook posts to online-travel reviews, even brief, informal pieces of writing that follow these rules get more likes and shares.

If everyone is a busy reader, everyone is a busy writer, too. That may make it tempting to sent as many messages as ________ as possible and hope for the best. But from essays to text messages organizing dinner plans, devoting time to the needs of readers has provable ________. If you are so busy that you write an undisciplined message which readers scan, ignore and delete, then you might as well have not ________ it at all.