6 . Human beings are not alone in having invented vaccination, while honeybees got there first and they can run what look like vaccination programmes, which has been confirmed by Gyan Harwood of the University of Illinois, Urbana-Champaign. Queen bees vaccinate their eggs before they are laid. But the question is how the queen receives her antigen supply, for she lives purely on royal jelly, a substance secreted by nurse bees when they are in the life stage of feeding the young. Dr Harwood wondered if the nurses combined the royal jelly they produced with pieces from pathogens they had consumed while eating something brought in from outside. To test this idea, they collected about 150 nurse bees and divided them among six queenless mini hives equipped with the young to look after. They fed the nurses on sugar-water, and for three of the hives they added Paenibacillus larvae, a bacterium causing a disease, to sugar-water. Dr Harwood and Dr Salmela labeled the bacteria with a certain dye, to make them easy to track. And, sure enough, microscope confirmed that Paenibacillus larvae were getting into royal jelly secreted by those bees which had been fed with the sugar-water. Moreover, examination of this royal jelly revealed higher levels of defensive substance, compared with royal jelly from bees that had not been mixed with Paenibacillus larvae. This substance is thought to help bee immune systems fight against bacterial infections. All told, these findings suggest that nurse bees are indeed, via their royal jelly, passing antigens on to the queen, then into eggs. They also mean, because the young receive royal jelly for the first few days after they hatch, the nurses are giving the young the second antigens. Each young bee is therefore being vaccinated twice.【小题1】What puzzled Dr Harwood from paragraph 2?A．What the royal jelly consists of.B．Where nurse bees receive pathogens.C．How the antigen come into the queen bees' bodies.D．Whether honeybees run vaccination earlier than man.【小题2】How did Dr Harwood develop his experiment?A．By dividing bees into different roles.B．By keeping track of the special bacterium.C．By changing the components of royal jelly.D．By observing nurse bees' different behaviors.【小题3】What can we infer according to the results of the experiment?A．Nurse bees are the key to vaccination for bee group.B．The nurse bees pass the antigen only to the queen.C．Bacteria-used royal jelly has fewer defense substances.D．Two vaccinations are given to young bees by caregivers directly.【小题4】Where is the text probably taken from?A．A pet guide.B．A social website.C．An official document.D．A medical magazine.

“Last night I heard him driving his pigs to market.”意思为_。A. 昨夜我听见他把他的猪赶到市场。B. 昨夜我听见他开车把猪送到市场。C. 昨夜我听见他鼾声如雷。D. 昨夜我听见他开车去了市场。

The homeless make up a growing percentage of America’s population. (1) , homelessness has reached such proportions that local government can’t possibly (2) . To help homeless people (3) independence, the federal govemments must support job training programs, (4) the minimum wage, and fund more low-cost housing. (5) everyone agrees on the number of Americans who are homeless. Estimates (6) anywhere from 600,000 to 3 million. (7) the figure may vary, analysts do agree on another matter, that the number of the homeless is (8) . One of the federal government’s studies (9) that the number of the homeless will reach nearly 19 million by the end of this decade. Finding ways to (10) this growing homeless population has become increasingly difficult. (11) when homeless individuals manage to find a (12) that will give them three meals a day and a place to sleep at night, a good number still spend the bulk of each day (13) the street. Part of the problem is that many homeless adults are addicted to alcohol or drugs. And a significant number of the homeless have serious mental disorders. Many others, (14) not addicted or mentally ill, simply lack the everyday (15) skills needed to turn their lives (16) . Boston Globe reporter Chris Reidy notes that the situation will improve only when there are (17) programs that address the many needs of the homeless. (18) Edward Zlotkowski, director of community service at Bentley College in Massachusetts, (19) it, "There has to be (20) of programs. What we need is a package deal. A．assistB．trackC．sustainD．dismiss

We had a great time at Tom's house yesterday. You ________ us. A ought join B must have joined C must join D should have joined

Is Fresh Air Really Good for You? We all grew up hearing people tell us to "go out and get some fresh air." 36 According to recent studies, the answer is a big YES, if the air quality in your camping area is good. 37 If the air you're breathing is clean — which it would be if you're away from the smog of cities — then the air is filled with life-giving, energizing oxygen. If you exercise out of doors, your body will learn to breathe more deeply, allowing even more oxygen to get to your muscles (肌肉) and your brain. Recently, people have begun studying the connection between the natural world and healing (治愈). 38 In these places patients can go to be near nature during their recovery. It turns out that just looking at green, growing things can reduce stress, lower blood pressure, and put people into a better mood (情绪). Greenery is good for us. Hospital patients who see tree branches out their window are likely to recover at a faster rate than patients who see buildings or sky instead. 39 It gives us a great feeling of peace. 40 While the sun's rays can age and harm our skin, they also give us beneficial Vitamin D. To make sure you get enough Vitamin D — but still protect your skin — put on sunscreen right as you head outside. It takes sunscreen about fifteen minutes to start working, and that's plenty of time for your skin to absorb a day's worth of Vitamin D. 1. 36 A: Fresh air cleans our lungs. B: So what are you waiting for? C: Being in nature refreshes us. D: Another side benefit of getting fresh air is sunlight. E: But is fresh air really as good for you as your mother always said? F: Just as importantly, we tend to associate fresh air with health care. G: All across the country, recovery centers have begun building Healing Gardens. 2. 37 A: Fresh air cleans our lungs. B: So what are you waiting for? C: Being in nature refreshes us. D: Another side benefit of getting fresh air is sunlight. E: But is fresh air really as good for you as your mother always said? F: Just as importantly, we tend to associate fresh air with health care. G: All across the country, recovery centers have begun building Healing Gardens. 3. 38 A: Fresh air cleans our lungs. B: So what are you waiting for? C: Being in nature refreshes us. D: Another side benefit of getting fresh air is sunlight. E: But is fresh air really as good for you as your mother always said? F: Just as importantly, we tend to associate fresh air with health care. G: All across the country, recovery centers have begun building Healing Gardens. 4. 39 A: Fresh air cleans our lungs. B: So what are you waiting for? C: Being in nature refreshes us. D: Another side benefit of getting fresh air is sunlight. E: But is fresh air really as good for you as your mother always said? F: Just as importantly, we tend to associate fresh air with health care. G: All across the country, recovery centers have begun building Healing Gardens. 5. 40 A: Fresh air cleans our lungs. B: So what are you waiting for? C: Being in nature refreshes us. D: Another side benefit of getting fresh air is sunlight. E: But is fresh air really as good for you as your mother always said? F: Just as importantly, we tend to associate fresh air with health care. G: All across the country, recovery centers have begun building Healing Gardens.

Reading aloud every day is one of most useful methods in learning English.A. aB. anC. theD. /

Much of the work in today's world is accomplished (完成) in teams. Most people believe the best way to build a great team is to gather a group of the most talented individuals. 46 Companies spend millions hiring top business people. Is their money well spent? 47 They focused on football, basketball and baseball. The results are mixed. For football and basketball, adding talented players to a team proves a good method, but only up to the point where 70% of the players are top talent: above that level the team's performance begins to decline. Interestingly, this trend isn't evident in baseball where additional individual talent keeps improving the team's performance. To explain this phenomenon, the researchers explored the degree to which a good performance by a team requires its members to coordinate (协调) their actions. 48 In baseball, the performance of individual players is less dependent on teammates. They conclude that when task interdependence is high, team performance will suffer when there is too much talent, while individual talent will have positive effects on team performance when task interdependence is lower. If a basketball star is, for example, trying to gain a high personal point total, he may take a shot himself when it would be better to pass the ball to a teammate, affecting the team's performance. Young children learning to play team sports are often told, "There is no I in TEAM." 49 Another possibility is that when there is a lot of talent on a team, some players may make less effort. Just as in a game of tug-of-war (拔河), whenever a person is added, everyone else pulls the rope with less force. 50 An A-team may require a balance — not just A players, but a few generous B players as well. 1. 46 A: It's not a simple matter to determine the nature of talent. B: Sports team owners spend millions of dollars attracting top talent. C: The group interaction and its effect drew the researchers' attention. D: Stars apparently do not follow this basic principle of sportsmanship. E: Several recent studies examined the role of talent in the sports world. F: Building up a dream team is more complex than simply hiring the best talent. G: This task interdependence distinguishes baseball from football and basketball. 2. 47 A: It's not a simple matter to determine the nature of talent. B: Sports team owners spend millions of dollars attracting top talent. C: The group interaction and its effect drew the researchers' attention. D: Stars apparently do not follow this basic principle of sportsmanship. E: Several recent studies examined the role of talent in the sports world. F: Building up a dream team is more complex than simply hiring the best talent. G: This task interdependence distinguishes baseball from football and basketball. 3. 48 A: It's not a simple matter to determine the nature of talent. B: Sports team owners spend millions of dollars attracting top talent. C: The group interaction and its effect drew the researchers' attention. D: Stars apparently do not follow this basic principle of sportsmanship. E: Several recent studies examined the role of talent in the sports world. F: Building up a dream team is more complex than simply hiring the best talent. G: This task interdependence distinguishes baseball from football and basketball. 4. 49 A: It's not a simple matter to determine the nature of talent. B: Sports team owners spend millions of dollars attracting top talent. C: The group interaction and its effect drew the researchers' attention. D: Stars apparently do not follow this basic principle of sportsmanship. E: Several recent studies examined the role of talent in the sports world. F: Building up a dream team is more complex than simply hiring the best talent. G: This task interdependence distinguishes baseball from football and basketball. 5. 50 A: It's not a simple matter to determine the nature of talent. B: Sports team owners spend millions of dollars attracting top talent. C: The group interaction and its effect drew the researchers' attention. D: Stars apparently do not follow this basic principle of sportsmanship. E: Several recent studies examined the role of talent in the sports world. F: Building up a dream team is more complex than simply hiring the best talent. G: This task interdependence distinguishes baseball from football and basketball.

Although we are very good friends I_George.A. have nothing in common withB. have something in common withC. have nothing in commonD. have much in common with

The result of every accident ,however ____,is a rise in the cost of insurance.A. radicalB. rareC. reluctantD. minor