Over the past decade or so, biologists have shown that we are filled with microbiomes (微生物组), inside and out. This microbiome,     1     (compose) of bacteria, fungi and viruses, profoundly influences our health and fitness and sometimes is even linked to our emotional state.

The oral microbiome gets far less attention, but we     2     (know) of it for a long time. In 1891, US dentist Willoughby D. Miller first proposed that bacteria could leave the mouth, travel to other parts of the body and cause disease. We only began to get supporting evidence in 1989, when researchers noticed that people who had experienced a heart attack were rated as having oral health that was about twice as poor as     3     of a control group. Even when age, social class and smoking habits     4     (account) possible factors, the results remained almost the same. A solid link seemed to be there.

More recently, thanks to DNA sequencing technology, by cataloguing the microbes in our mouths, we are now finding that the types of bacteria people have     5     (live) there seem to be associated with a growing number of conditions like cancer. Perhaps the most striking example is Alzheimer’s disease. It can be found that people with gum (牙龈) disease are     6     increased risk of developing this condition, which slowly robs people of their memories, personalities and cognitive function. However, until recently, it was unclear     7     poor oral health was a contributing cause of Alzheimer’s or a consequence of it.

Then, in 2019, scientists discovered some species of bacteria known     8     (cause) gum disease — including one called Porphyromonas gingivalis — which are inside the brains of people who died of Alzheimer’s disease. If the mouth bacteria were getting into the brain, that lent weight to the idea that they could be a cause of Alzheimer’s.

Researchers are still trying to grasp how this could happen.     9     the mechanism is, they note that there may be a way you can protect yourself in advance. Dental scientists at the University of Melbourne, Australia, is developing a vaccine against gum disease     10     you can reduce the risks of gum diseases significantly.

2 . It was dinnertime at Grandma and Grandpa's farm. It was a feast (盛宴) but without ________ occasion. We had chicken, potatoes, green salad, corn and fruit salad. We sat at the table. Grandma ________ the food to Grandpa and their girls. Grandpa said, “Looks delicious. I'm as ________ as a bear.”

As soon as Grandpa picked up his ________, they heard a car drive up. Grandma opened the door, and in came Aunt Maud. “Come in! You’re just in time,” Grandpa said. Then in came Aunt Dessie, Aunt Clara, friends, and their families. Grandma was a little ________, “I never expected so many guests to come, but I can ________ it.”

Grandpa sat in the doorway. There was little ________ in the kitchen behind his chair. So he got up and pulled his chair in so people could ________. But when he sat down again a strange thing happened: His plate had ________ before his eyes! He put his fork down, thinking to himself, “Well, there seems no ________ for my plate anymore.”

Grandma tried to serve the kids some water, but Aunt Dessie ________ her, “We’ll take care of ourselves.” Then everyone started ________ around the sink (水池) and cupboard to drink water. Kids were thirsty! There were lots of kids. Grandma had enough food for four, not twenty-four! ________, Aunt Dessie helped Grandma make more dishes. The girls ________ to help, but Aunt Dessie said they were too ________ and had better stay at the table so that they wouldn’t do more harm than good. Grandma added some more foods to everyone's plate. There was lots of laughter. No one doubted they had a good time.

They never found out who used Grandpa’s plate, but did know that he enjoyed the reunion and that was enough!

Sadness is a natural part of the human experience. Clinical depression, however, is an entirely different matter, and much more serious. Clinical depression, sometimes called major depression, is a biologically based brain disorder that affects one’s thoughts, feelings, behavior and physical health. When people complain that they feel terrible, have no interest or take no pleasure in things, have trouble sleeping, lack energy, have a poor appetite, or cannot concentrate, there definitely is a possibility that the person is clinically depressed.

Depression in its many forms affects more than 6.5 million of the 35 million Americans who are 65 years or older. Most old people with depression have suffered from episodes of the illness through much of their lives. But some have a first onset late in their lives — it may happen to those in their eighties and nineties. Depression in older people is closely associated with dependency and disability and causes great suffering for the individual and the family.

Many old people and their families don't recognize the symptoms of depression, aren't aware that it is a medical condition, and don't know how it is treated. Others may mistake the symptoms of depression as signs of dementia (痴呆). Meanwhile, many old people think that depression is a character flaw, so they blame themselves for their illness and are too ashamed to seek help. Others worry that treatment would be too costly.

Old people with depression rarely try to get treatment for the illness. Unrecognized and untreated depression has fatal consequences in terms of both suicide and non-suicide mortality (自杀或非自杀造成的死亡). The highest rate of suicide in the U.S. is among old white men. Depression is the single most significant risk factor for suicide in that population. Tragically, many of those people who go on to commit suicide have reached out for help — 20 percent see a doctor the day they die, 40 percent the week they die and 70 percent in the month they die. Yet depression is frequently missed.

9 . As we know, it is very important that a firm should pay attention to the training of its staff as there exist many weak parts in its various departments.     1     It is defined when a firm considers its training needs, which are in turn based on job descriptions and job specifications.

A job description should give details of the performance that is required for a particular job, and a job specification should give information about the behavior, knowledge and skills that are expected of an employee who works in it.     2     This specifies what the Training Department must teach for the successful performance of the job, and also the best methods to use in the training period.

    3     Successful training programmes depend on an understanding of the difference between learning about skills and training in using them. It is frequently said that learning about skills takes place “off the job” in the classroom, but training in using these skills takes place “on the job,” by means of such activities as practice in the workshop.

    4     The success of such a programme depends not only on the methods used but also on the quality of the staff who do the training. A company can often check on savings in time and cost by examining the work performed by the workers and technicians who have completed a training programme. The evaluation of management training is much more complex than that.

10 . A new study describes a surprising number of coastal marine invertebrate (无脊椎动物) species thriving in floating communities in deep ocean waters. What's their secret? They are colonizing ever-expanding rafts of plastic debris.

The study was led by researchers from the Smithsonian Environmental Research Center (SERC) and the University of Hawaii (UH) at Mānoa. They found a diverse range of taxonomic groups of coastal species in the eastern North Pacific Subtropical Gyre (北太平洋副热带流涡区) on over 70 percent of the plastic debris they examined. Not only that, but the debris carried more coastal species than open ocean species. “This discovery suggests that past biogeographical boundaries among marine ecosystems-established for millions of years-are rapidly changing due to floating plastic pollution accumulating in the subtropical gyres,” said lead author Linsey Haram, research associate at SERC.

These floating communities, or “neopelagic (新远洋的) communities” , in deep oceanwaters were only recently discovered by scientists. The researchers looked at 105 plastic samples collected by The Ocean Cleanup during their 2018 and 2019 expeditions in the North Pacific Subtropical Gyre, which occupies most of the northern Pacific Ocean. “We were extremely astonished to find 37 different invertebrate species that normally live in coastal waters, over triple the number of species we found that live in open waters, not only surviving on the plastic but also reproducing. Our results suggest coastal organisms now are able to reproduce, grow, and persist in the open ocean---creating a novel community that did not previously exist, being sustained by the vast and expanding sea of plastic debris," said Haram.

This phenomenon will take a heavy toll on marine ecosystems. “The Hawaiian Islands are neighbored in the northeast by the North Pacific garbage patch. Debris that breaks off from this patch constitutes the majority of debris arriving on Hawaiian beaches and reefs,” said Nikolai Maximenko, senior researcher of the UH. “In the past, the fragile marine ecosystems of the islands were protected by the very long distances from coastal communities of Asia and North America,” Maximenko adds. “The presence of coastal species persisting in the North Pacific Subtropical Gyre near Hawaii is a game changer that indicates that the islands are at an increased risk of colonization by invasive species.”