In the black and white photo, the panther is hardly visible, but as soon as we add colour, it's easy to (26)______ the predator from the background. Why? Because in the black and white picture you are only seeing the surfaces according to how much light they reflect. The colour lets you see the quality of light as well as the quantity and reveals the panther. In a real-life jungle situation, this might save your life, and the importance of colour (27)________ might therefore explain why people are generally more fearful in the dark.
The sense of sight, however, is about (28)_______ more than what our eyes actually see. (29)_______what we see is pretty meaningless - it's just patterns of light. We need the brain to interpret these patterns, and it tends to do this in ways (30)________ have proved useful in the past. This is usually helpful, but sometimes this means the brain actually creates an illusion by trying to make sense of information from the eyes.

Insomnia is almost twice as common in women as in men, but even those who feel they haven't slept a wink probably have had more sleep than they think. Nowadays we believe that we need to get eight hours' uninterrupted sleep; but in the Middle Ages, people would often get up for a while in the night, wide awake, to chat or even visit neighbours. However, it is true to say that having artificial light sources has meant that we tend to get less sleep overall than we used to.
According to recent research, nearly half of US adults admitted to falling asleep unintentionally during the day at work, on public transport or, worryingly, while driving. Twice as many men as women admit to nodding off while driving. In many cultures, having a snooze (though not while driving!) is much more culturally acceptable than in the US, and it might help to make the roads safer. Apparently, a short nap is more refreshing than a cup of coffee.
Once parents stop managing their bedtimes, teenagers usually start going to bed much later. However, because their brains are still developing, they still need between nine and ten hours a night, as much as a sixyear-old. Late-night studying, however, does have some advantages, as there is vidence that sleeping when you've just learnt something new will help your memory to retain it. 80% of people need between six and nine hours' sleep a night. But if you are used to sleeping like a log for nine hours, can you force yourself to get used to having only six? Apparently not, but you an catch up on missed sleep by having a lie-in, and it even works if you have the lie-in on the morning before you miss the sleep.

Antibiotics have been responsible for saving the lives of millions of patients. But this success has come at a price. The growing resistance of many bacterial strains to the curative effects of antibiotics is such a concern that it has been referred to, in some quarters, as the greatest threat to our continued existence on earth. We have become careless not only in our reliance on the quick fix of medicine but also in taking the availability of antibiotics for granted, using them incorrectly. This has given rise to a new form of superbacteria, a type which is able to fight off antibiotic treatment with ease.
Although their resistance to antibiotics has been built up over a long period of time, bacteria actually replicate extraordinarily quickly, and any resistance developed is also duplicated as they divide. In addition, those bacteria carrying resistance genes happen to spread those genes further via 'horizontal gene transfer'. What makes the spread of these strains more difficult to control is that it occurs in a cyclical process. In the case of humans, when a person becomes infected and the resistant bacteria set up home in the gut, the sufferer has two choices: look for help or stay at home. In seeking medical assistance, whether through an appointment to visit their local doctor, or taking themselves to hospital, they contaminate other patients, later to be discharged and sent home. The resistant bacteria then spread out into the local community. This is also the end result if the infected person decides not to seek any medical assistance at all: they keep the bacteria at home and allow them to breed without treatment.
We now face a global emergency as antibiotic-resistant bacteria are beginning to emerge more rapidly and frequently than ever before. Not only has this created a potential health crisis but it is also unlikely to be tackled any time soon, as the powerful pharmaceutical companies are primarily driven by profit and see little benefit in researching and creating new antibiotics. It simply does not work on the balance sheet, and so it falls to governments and individuals around the world to find ways to manage the crisis. Coordinating such efforts will not be easy.