单选题Bystanders, ______, ______ as they walked past lines of ambulances.

单选题I asked my mother if I could go out, and she ______.

单选题It stands to reason that if he never prepares his lessons, be is not going to make good progress.

单选题When the writer told an ex-colleague about the man in the park, the ex-colleague ______.

单选题According to the passage, in the 1930s, abstract art was seen as ______.

单选题The older I grow the more impressed I am with the role of luck or chance in life. To be born when and where one finds himself is, of course, from the point of view of the individual pews the sheerest luck of all--good or bad. There are millions now living in America who would long since have been dead, had they been born or had remained in countries of their parents' origins. Luck does not determine or explain achievement--merit often plays a preponderant role. This is obvious when we observe the differences in performances among those who have a roughly common environment and are judged by a single, relevant standard. But even to be in a position to be evaluated on one's merits is a matter of luck or good fortune. Sometimes those who are qualified, and more often, those who are potentially qualified never get the chance. Sometimes the qualified have the good luck of competing against the poorer qualified or the bad luck of competing against the better qualified-circumstances usually beyond the control of the persons affected. Yet, in every competition this is an important factor. The distribution of wealth in this world depends almost as much on luck as on energy, foresight and skill. These latter virtues are decisive as a rule when the luck of opportunity is common. But often it is not, as the varying portions of individuals' inheritance testify. Even when the opportunity is common, results may not reflect merit or demerit. When we read of the actions for which individuals have run afoul of the law, it is only the weakness and poverty of our imagination that prevent us from grasping the series of events--all caused to be sure--whose conjunction could have landed us in the same predicament. If our temper had flared up when a deadly weapon was available, might we not be in the dock? Regardless of legal guilt or innocence, being charged with, or involved in, a crime is often a matter of luck. We never know when we may be falsely accused. Does belief in luck tend to an acceptance of the status quo? Not necessarily--although there is nothing wrong in accepting the status quo, if any feasible alternative to it is likely to be worse. When we realize what we owe to luck, it tends to cure us of overweening pride, of smugness and self-righteousness. For whatever our achievements we will note that they are not a consequence only of our worth, or of our efforts and virtues alone. Success always depends upon the cooperation of other persons and things, on the happy concert of time, place and opportunity--the absence of any one of which might have spelled failure.

单选题A suitcase with shirts, trousers and shoes ______ stolen from the car.

单选题As a result of their frequent litters, rabbits have the reputation of being ______.

单选题I much prefer factual books such as biographies to______ of any kind.

单选题 A major reason for conflict in the animal world is territory. The mate animal establishes an area. The size of the area is sufficient to provide food for him, his mate and their offspring. Migrating birds, for example, used up the best territory in the order of "first come, first {{U}} {{U}} 1 {{/U}} {{/U}}." The late arrivals may acquire {{U}} {{U}} 2 {{/U}} {{/U}}, territories, but less food is available, or they are too close to the {{U}} {{U}} 3 {{/U}} {{/U}}of the enemies of the species. {{U}} {{U}} 4 {{/U}} {{/U}}there is really insufficient food or the danger is very great, the animal will not {{U}} {{U}} 5 {{/U}} {{/U}}. In this way, the members of the species which are less fit will not have offspring. When there is conflict {{U}} {{U}} 6 {{/U}} {{/U}}territory, animals will commonly use force, or a show of force, to decide which will stay and which will go. It is interesting to note, {{U}} {{U}} 7 {{/U}} {{/U}}, that animals seem to use only the minimum amount of force {{U}} {{U}} 8 {{/U}} {{/U}}to drive away the intruder. There is usually no kilting. In the case of those animals which are capable of {{U}} {{U}} 9 {{/U}} {{/U}}each other great harm, {{U}} {{U}} 10 {{/U}} {{/U}}is a system for the losing animal to show the winning animal that he wishes to submit. When he shows this, the victor normally stops fighting.

单选题Scientists have long understood that supermassive black holes weighing millions or billions of suns can tear apart stars that come too close. The black hotels gravity pulls harder on the nearest part of the star, an imbalance that pulls the star apart over a period of minutes or hours, once it gets close enough. Scientists say this uneven pulling is not the only hazard facing the star. The strain of these unbalanced forces can also trigger a nuclear explosion powerful enough to destroy the star from within. Matthieu Brassart and Jean-Pierre Luminet of the Observatoire de Paris in Meudon, France, carried out computer simulations of the final moments of such an unfortunate star's life, as it veered towards a supermassive black hole. When the star gets close enough, the uneven forces flatten it into a pancake shape. Some previous studies had suggested this flattening would increase the density and temperature inside the star enough to trigger intense nuclear reactions that would tear it apart. But other studies had suggested that the picture would be complicated by shock waves generated during the flattening process and that no nuclear explosion should occur. The new simulations investigated the effects of shock waves in detail, and found that even when their effects are included, the conditions favor a nuclear explosion. "There will be an explosion of the star — it will be completely destroyed," Brassart says. Although the explosion obliterates the star, it saves some of the star's matter from being devoured by the black hole. The explosion is powerful enough to hurl much of the star's matter out of the black hole's reach, he says. The devouring of stars by black holes may already have been observed, although at a much later stage. It is thought that several months after the event that rips the star apart, its matter starts swirling into the hole itself. It heats up as it does so, releasing ultraviolet light and X-rays. If stars disrupted near black holes really do explode, then they could in principle allow these events to be detected at a much earlier stage, says Jules Hatpern of Columbia University in New York, US2. " It may make it possible to see the disruption of that star immediately if it gets hot enough," he says. Brassart agrees. " Perhaps it can be observed in the X-rays and gamma rays, but it's something that needs to be more studied," he says. Supernova researcher Chris Fryer of the Los Alamos National Laboratory in Los Alamos, New Mexico, US3, says the deaths of these stars are difficult to simulate, and he is not sure whether the researchers have proven their case that they explode in the process.

单选题The passage mentioned ______.

单选题Now let"s begin with question Number 1.

单选题He is setting out for the country and sends you a thousand thanks and ______. A. compliments B. complements C. satisfactions D. supplements

单选题The bribe and the bridegroom were overwhelmed in happiness when their family offered to take them to Rome to _______the marriage.

单选题In general, matters which lie entirely within state borders are the ______ concern of state governments. A. extinct B. excluding C. excessive D. exclusive

单选题Bangladeshi communities that are already being poisoned by arsenic-tainted(含砷)groundwater are facing an appalling new threat. Their rice and vegetables are also laced with high levels of arsenic. The health effects of eating such tainted food are not yet known, but the ramifications(门类)could be enormous. The WHO says contaminated drinking water alone could kill 270,080 Bangladeshis over the next decade. In a terrible irony, arsenic entered the Bangladeshi water supply when UNICEF and other international agencies sank millions of tube veils to provide clean drinking water. But the wells tapped into groundwater contaminated by arsenic from sedimentary deposits deep below Bangladesh. To deal with the problem, UNICEF and the World Bank have been testing water from wells and marking them safe or dangerous—but that testing program has been found to be flawed. To make matters worse, water from the wells is also used to irrigate paddy(水稻)fields. However, until now it wasn't known whether or not the rice was accumulating-arsenic. Tests on rice samples from around Bangladesh had found that arsenic levels did indeed vary according to the strength of local arsenic contamination in the soil and groundwater. Arsenic levels in different varieties of rice ranged from about 0.05 to 1.8 parts per million. In Europe and the US, levels are around 0.05 parts per million. The WHO recommends a maximum level of 0.01 parts per million in drinking water—but therefore, no guidelines for levels in foods. Ravi Naidu at CSIRO in Adelaide and his colleagues have been studying the uptake of arsenic from the soil by Bangladeshi crops. Their data shows that arum, a popular vegetable, has arsenic levels of nearly 150 parts per million. It is usually grown in wet zones adjacent to the tube wells. But some vegetables such as spinach and beans are relatively free from arsenic. The rice grains studied by Naidu's team had arsenic levels that ranged from undetectable to over 1.6 parts per million. Their calculations show that nearly 30 per cent of the total arsenic intake for people in Bangladesh may be coming from their food. If the body can absorb arsenic from food—and this is yet to be proven—then merely tackling drinking water contamination will not be enough. Researchers fear that paddy fields will continue to be irrigated from poisoned tube wells because Bangladesh does not have enough arsenic-free water for agriculture.

单选题Monique is studying business administration because she wants to be a highly paid ______ in a large company. A. primitive B. executive C. conservative D. representative

单选题Professor Taylor's talk has indicated that science has a very strong ______ on the everyday life of non-scientists as well as scientists.