Read the following article and select the best answer. Article: Life on earth depends on water, and there is no substitute for it. The current assumption is that our basic needs for water--whether for drinking, agriculture, industry or the raising of fish--will always have to be met. Given this premise , there are two basic routes we can go; more equal access to water or better engineering solutions. Look at the engineering solutions first. A lot of my research concentrates on what happens to wetlands when you build dams in river basins, particularly in Africa. The ecology of such areas is almost entirely driven by the seasonal changes of the river--the pulse of the water. And the fact is that if you build a dam, you generally spoil the downstream ecology. In the past, such problems have been hidden by a lack of information. But in the near future, governments will have no excuses for their ignorance. The engineers' ability to control water flows has created new kinds of unpredictability, too. Dams in Africa have meant fewer fish, less grazing and less floodplain agriculture, none of which were expected. And there average economic life is assumed to be thirty years. Dams don't exist forever, but what will replace them is not clear. The challenge for the future is to find new means of controlling water. Although GM technology will allow us to breed better dry-land crops, there is no market for companies to develop crops suitable for the micro-climates of the Sahel and elsewhere in Africa. Who is going to pay for research on locally appropriate crops in the Third World? Question: What's the main idea of this passage? - The engineering solutions to water resource and their limitation. - The challenge for the future. - The basic means of controlling water. - The challenge for developing crops.
The engineering solutions to water resource and their limitation.

Read the following article and select the best answer. Article: No more batteries,no more chargers and no more wires.This is the future promised by "wireless power".a means of broadcasting electricity through the air to laptops,iPods and other gadgets without the need for cables and sockets . Wireless lighting,audio speakers and digital picture frames are expected to be among the first commercial products exhibited in Las Vegas this week at the International Consumer Electronics Show,the world's biggest gadgets tradeshow. Experts believe this is just the beginning and that eventually wireless electricity could do for battery life what WiFi did for,the Internet.In a world without wires,laptop users in cafes and airport terminals would be inside an "electricity hotspot" and no longer have to delve an awkwardly located socket. "You'd be able to buy.a desk that charged any gadget placed on it, or power any PC you put on top," said James Holland,editor of gadgets website Eleetricpig.co.uk."If each room had wireless power,you'd know that once you walked through the front door your nmbile would start charging up--even while still in your bag or pocket.You'd never need to hunt for the right charger again." Among the companies showcasing the ambitions technology at CES is Power Beam.Its system turns electricity into an invisible laser, then beams it as heat,across the room to a solar cell that conveys it back into dectricity. David Graham,the co-founder of Power Beam,said:"We're going to delete the word 'recharge' from the English dictionary.If your,cell phone is recharging on your desk.all day,you won't be thinking about.it." The Silicon Valley company can currently use a laser to generate about 1.5 watts of power to _ a solar.cell 10 meters away.This, sould be enough to power an electronic speaker or small LED lights,but not enough to operate a laptop,which requires about 30 to 50 watts.However,Graham said that the technology could comfortably be scaled up . Power Beam insists its laser does not lead to a risk to users' health because it is simply moving heat from one place... Question: According to James Holland,we know that _ . - a cell phone Can be powered only on a desk - gadgets can be charged in a loom with wireless power - a right charger is needed - each room should have wireless power
gadgets can be charged in a loom with wireless power

*Question*
Read the following article and select the best answer. Article: A few years ago it was popular to speak of a generation gap, a disagreement between young people and their elders.Parents said that children did not show them proper respect and obedience , while children complained that their parents did not understand them at all.What had gone wrong? Why had the generation gap suddenly appeared? Actually the generation gap has been _ for a long time.Many people argue that a gap is built into the fabric of our society. One important cause of the generation gap is the chance that young people have to choose their own ways of life.In more traditional societies, when children grow up, they are expected to live in the same area as their parents, to marry people that their parents know and agree to, and to continue the family occupation .In our society, young people often travel great distances for their education, move out of the family home at an early age, marry or live with people whom their parents have never met, and choose occupations different from those of their parents. In our easily changing society, parents often expect their children to do better than they did: to find better jobs, to make more money, and to do all the things that they were unable to do.Often, however, the strong desire that parents have for their children are another cause of the disagreement between them.Often, they discover that they have very little in common with each other. Finally, the speed at which changes take place in our society is another cause of the gap between the generations.In a traditional culture, elderly people are valued for their wisdom, but in our society the knowledge of a lifetime may become out of date overnight.The young and the old seem to live in two very different worlds, separated by different skills and abilities. No doubt, the generation gap will continue to be a feature of American life for some time to come.Its causes are rooted in the freedom and changes of our society, and in the rapid speed at which society changes. Question: Which of the following statements is true according to the passage? - Parents should be strict with their children. - The younger generation should value the older generation for their wisdom. - The generation gap is partly caused by the older generation. - The generation gap does not exist in American society.
**Answer**
The generation gap is partly caused by the older generation.