Read the following article and select the best answer. Article: Scientists have claimed a milestone in the drive for new energy--development of the first practical artificial leaf, an advanced solar cell that imitates the process,called photosynthesis ,that green plants use to make sunlight and water into energy. "A practical artificial leaf has been a dream of scientists for decades,"said Daniel Nocera,who led the research team."We believe we have made it.The artificial leaf shows particular promise as an inexpensive source of electricity for homes of the poor in developing countries. One can imagine villages in India and Africa soon purchasing an affordable basic power system based on this technology." The leaf is like the shape of a poker card but thinner.Placed in water in a bright sunlight,it could produce enough electricity to supply a house in a developing country with electricity for a day by splitting water into hydrogen and oxygen, which are stored in a fuel cell to produce electricity. The"artificial leaf"is not a new concept.The first artificial leaf was developed more than a decade ago by John Ttlrner.However, it was impractical for wider use,as it was composed of rare,expensive metals and was highly unstable with a lifespan of barely one day. Nocera's new leaf overcomes these problems.It is made of inexpensive materials that are widely available,works under simple conditions and is highly stable.Laboratory studies showed that it could operate continuously for at least 45 hours without a drop in activity. The key to this breakthrough is Nocera's recent discovery of several new powerful, inexpensive catalysts,which are able to accelerate the chemical reaction under simple conditions.Right now, Nocera's leaf is about 10 times more efficient at carrying out photosynthesis than a natural leaf.Yet he is optimistic that he can boost the efficiency of the device much higher in the future. Question: Daniel Nocera describes his artificial leaf as promising in _ . - making an artificial plant that can feed itself. - finding a new kind of catalyst to produce electricity. - changing the sunlight and water into electricity directly - providing electricity for the poor family at a low cost
providing electricity for the poor family at a low cost

(Question)
Read the following article and select the best answer. Article: There are times when nothing seems to be working in our favor. We may use complaining as a coping mechanism (,) when we are truly unhappy. However, there are many times when we don't try our best and just want things to work our way. We may try to cover our faults by complaining about the unfairness of it all. These are expressive complaints where the complainer just wants to let out his/her anger or frustration, with no real intention of solving the problem. The complainer expects pity and recognition from the listeners although the results often disappoint him/her. Sometimes, we use complaints as a conversation starter. Conversations that start with a complaint often have a domino effect. It may cause the listener to include his/her complaints in the conversation as well, which makes you think that you are not the only one facing problems. However, your good feeling won't last long as long as you are always focusing on the negative. When complaining becomes a habit, you complain to anyone that comes around. Negativity that comes from complaining kills creativity and innovation . Habitual complainers are less likely to come up with new ideas, as they are busy finding faults and discourage others from trying new things by making them feel that they won't work. When you spend time with people who constantly complain, you are likely to view things in a negative light. This will make things worse. This can affect the way you perceive your own situation, and even the people around you. Though expressing your feelings may momentarily improve your state of mind, it could sometimes have a bad effect on the listener's state of mind. A recent study has shown that at social gatherings while people who are unhappy may join you when you play the victim at the beginning, the majority would start avoiding you because of your negativity. Question: Why do people who don't try their best often complain? - They want to get others' pity. - It is the best way to let out their anger. - They try to find an excuse for their faults. - They hope to get a solution to their problems.
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They try to find an excuse for their faults.

Read the following article and select the best answer. Article: According to new research,there could be a social hierarchy attached to where people stand in the lift.More senior men stand at the back,young men in the middle and women of all ages at the front. Most people know that awkward feeling when you shuffle into an elevator with other people and try not to make eye contact. But new research suggests it may be down to a subconscious power struggle being played out as you make your way up or down. A study found that people decide where they stand based on a micro social hierarchy,established within seconds of entering the lift. Rebekah Rousi,a Ph.D.student in cognitive science,conducted all ethnographic study of elevator behaviour in two of the tallest office buildings in Adelaide,Australia. As part of her research,she took a total of 30 lift rides in the two buildings,and discovered there was an established order to where people tended to stand. In a blog for Ethnography Matters,she writes that more senior men seemed to direct themselves towards the back of the elevator cabins. She said,"In front of them were younger men,and in front of them were women of all ages." She also noticed there was a difference in where people directed their gaze half way through the ride. Men watched the monitors,looked in the side mirrors(in one building)to see themselves,and in the door mirrors(of the other building)to also watch others. Women would watch the monitors and avoid eye contact with other users(unless in conversation)and the mirrors,she writes. The doctorate student concluded it could be that people who are shyer stand toward the front,where they can't see other passengers,whereas bolder people stand in the back,where they have a view of everyone else. Question: What causes people to feel uncomfortable when entering the an elevator? - The manner people went into the lift. - The limited space in the lift. - The subconscious power struggle. - The micro social hierarchy.
The subconscious power struggle.