1 . Americans spend billions on vitamins, multivitamins for their health, but a review of numerous studies concluded there is little to no evidence that some of those vitamins prevent heart disease, cancer or death.

The report, released by the U.S. Preventive Services Task Force last week, concluded that “recent evidence is not enough” to determine whether vitamins actually help or hurt your health, based on 84 studies, 52 of which were done since 2014. Vitamins examined included vitamins A, B, C, D and E, as well as other multivitamins.

“Our suggestion is neither for nor against taking vitamins, or combinations of those nutrients (营养物质). We just don’t have enough evidence,” said Dr. John Wong, a doctor in the Department of Medicine at Tufts Medical Center who was involved in the report.

While the finding is that vitamins don’t have any benefits to “healthy, non-pregnant (未怀孕) adults”, it doesn’t apply to “children, people who are pregnant or may become pregnant, or people who are hospitalized.”

The Task Force admitted it makes sense that people would take vitamins in hopes of health benefits, as some shortage may lead to illness. But experts agreed the best way to get good health and prevent cancer is a balanced diet and regular physical activity.

“The suggestion across all organizations about vitamins is to eat a balanced diet, and then the key tends to be on plenty of fruit and vegetables and less junk foods,” Wong said.

Wong added people should refer to their health doctors to determine if any vitamins are worth taking. He said this suggestion should also serve as a need to further research into proving the official benefits and risks for each vitamin.

2 . Steph Clemence always intended to go to college. But life has a(an) _________ throughout her early childhood years to _________ barriers. Growing up, she led a nomadic (漫游的) life because her mother, who remarried several times, was always on the _________. By the time of high school, Steph had lived in 25 places.

When her stepfather died in a car accident, leaving her mother to support three daughters on a(an) _________ income, paying for college became a serious question. But she still tried to figure out what to do with a life so _________ her plan for schooling.

The _________ came one afternoon when she was cleaning her bedroom. She _________ a thick document where she found a handout titled “Mrs. Clark’s Book List” by her high school English teacher Dorothy Clark.

It wasn’t homework, but it could be a(an) _________ for those not able to receive higher education due to _________ problems like her. The teacher had spent months creating a list of 153 books whose contents would be as __________ as a two-year study at an arts college.

Steph studied the list. Each of those books __________ her to learn more. The reading list was also a(an) __________ in her everyday life, even __________ with her on vacations to find out the next book. She never did get to college, but has now only four books left before __________ the list. She wishes she could thank Mrs. Clark for how reading the __________ on the list has changed her life.

3 . When I was a practice teacher in a middle school，the students in my class were always making ______，and had no interest in chemistry. So I decided to do ______to change their______ towards chemistry.

The evening before I would teach all by myself，I gave a piece of paper to everyone. I told them to write ______ they wanted on the paper and handed it in and then I could tell what each one had ______ .All the students said I _____ be longsighted(远视)．Then I stood ______ my back towards them. I didn't turn back ______ they had finished and ______ all the paper in a cardboard case.

I turned the cardboard case with the bottom(底部)towards the students，and told them calmly what each one had written on the paper. The students were surprised，______ that I had learned their ______ completely in such a short time.

I told them the truth and they were ______ at my brightness：there were five lines of students in the classroom，and every line had ten students. I had written serial number(from 1 to 50 )on every ______ of the paper in a chemical reagent(试剂)that cannot be seen ______eyes，and then gave ______out to the students according to the groups of their seats. After the paper was ______ in，I used______ chemical reagent onto the corner of the paper. Thus the serial number was ______！

______ ，the students became ______ interested in chemistry，and we became good friends.

4 . Banff National Park is home to an amazing wildlife population. But the busy Trans Canada Highway that cuts through the park is a hazard to the lovely animals. To address the problem, Banff first put-up wildlife fencing on either side of the highway to discourage animals from entering the busy road. Then, since 1996, they’ve opened six wildlife overpasses and 38 underpasses to help the animals cross the highway in safety. I was fortunate to visit Banff’s Red Earth Overpass with Trevor Kinley, the project manager with Parks Canada. He told me that so far, they have documented 10, 000 safe animal crossings on this overpass alone. “ Some animals have learned how to use the crossings much more quickly than others. Black bears are the fastest learners, followed by deer. Wolves and lions take the longest to work out how to use them, ” Kinley said, laughing. “ But those animals that are slower to adapt are usually more capable and determined at figuring out the safest way to cross those overpasses and underpasses. ”

There is some criticism (批评) that channeling so much wildlife into a few bridges and tunnels is like making a trap for the animals, offering big animals an easy meal on either side. “ But research has shown that this is not the case, ” Kinley assured me. “ There are no more killings around the crossings than there are anywhere else in the park. ”

Walking over the Trans Canada and then walking underneath through one of the tunnels, I was amazed to see the fresh tracks of black bears, wolves, deer and many kinds of smaller animals. Somehow, all these animal footprints made me so happy, knowing that all this wildlife was passing safely under and over the longest road in Canada.

Hopefully, the success of the wildlife crossings in Banff will continue to inspire similar solutions around the world, where human pressure on wildlife continues to grow.

5 . Wu Ming, a young German born after 1995, is a big fan of Chinese culture. As he thought some diseases can’t be treated _______ with Western medicine, he decided to _______traditional Chinese medicine (TCM). In 2015, Wu came to Henan province, where a strong TCM culture can be _______. After a year of learning, he _______ the language barrier and started to learn Chinese medicine. Wu always _______ some Chinese herbal medicine by himself to know their flavours and effects, just like Shen Nong, a character in Chinese legend. In Wu’s opinion, TCM is one of the best-preserved _______ of Chinese culture.

Studying TCM also _______ Wu’s mind and lifestyle. He used to be _______ to electronic devices, playing video games every night. Instead of being trapped in the fast-paced but unhealthy daily _______, he now lives a(n) ________ and peaceful life, practicing good habits like drinking tea and reading.

Wu ________ what he has learned to help his family. He always provides his family members with some advice about staying fit after ________ their skin or tongues online. Over time, his family gradually began to understand his ________ for TCM.

Wu thinks there’s no big difference between China and Western countries. “________ comes from being out of touch”, said Wu. He plans to run a traditional Chinese clinic in Germany, which could serve as a(n) ________ between the two countries and publicize TCM and its culture.

8 . The Best National Parks to Visit in Winter

While most parks tend to draw families in the summer and fall, there are also ideal spots for adventurous winter trips.

The country’s oldest and best-known national park takes on an almost otherworldly atmosphere in winter: the air filled with rolling steam, the strong colors of hot springs, the surrounding white landscapes, let alone the impressive wildlife during this time, like bison, wolves, and playful red foxes. Just book a guided hiking tour to get a ranger’s perspective on the park and local people.

With its giant red rocks and unique trees, you’ll feel like stepping onto a foreign planet as you spend hours hiking the Panorama Loop or Maze Loop. The park is recognized as an International Dark Sky Park, featuring virtually zero light pollution and the country’s best views of a starry sky.

A significantly lower number of visitors in winter means you can take in unblocked views of the South Rim, and get to see the rare beauty of the Grand Canyon dusted with snow. For those adventurous and daring, it is recommended to hike the Bright Angel Trail and take the chance to see the canyon’s wintertime wildlife, including mule deer, elk, and bald eagles.

Surprise! Not all wintertime national park trips need to involve snow. Virgin Islands National Park is most famous for its white-sand beaches. You can also hike inland to visit old sugar plantations, or venture out to the water to swim along with sea turtles and manta rays. You will definitely enjoy a different winter here.