What makes us human？Is it our thoughts？Our emotions？Our behavior？

All of these things make us who we are，but at the center of it all lies the genome — the genes inside our bodies that determine everything from our hair color to our intelligence. But if we could change our genome，would we still be human？

Recently，a group of scientists from the US and South Korea worked together to successfully“edit”a human embryo（胚胎）and remove a genetic mutation（变异）that would have led to heart disease. This was achieved with the help of CRISPR-a gene — editing tool that allows scientists to edit the genome by cutting，changing or adding to parts of it.

Scientists involved in DNA editing are certain about the good of their work，and hope that in the future，diseases could simply be“edited out”.

However，others aren't so sure. People are worried that the science could be used not only to remove life-threatening illness，but also to make a“perfect”baby whose DNA has been chosen to improve its intelligence or other qualities. They say that this is a shallow way of thinking about raising children.

“It makes you think about who we are as people，and it makes you ask if humans should use the kind of power…that is changing human evolution（进化），”Jennifer Doudna of the University of California said.

Still，others worry that DNA editing could be turned into an expensive service that would only be available to the people who could afford it. That might mean the rich would be given another advantage in a world where they already have plenty of them.

“You could find wealthy parents buying the technology for their children, leading to even greater inequality than we already live with,”Marcy Darnovsky, director of the San Francisco Center for Genetics and Society, said.

   What should you think about when trying to find your career? You are probably better at some school subjects than others.  These may show strengths that you can use in your work. A boy who is good at mathematics can use that in an engineering career. A girl who spells well and likes English may be good at office work.  So it is important to know the subjects you do well in at school. On the other hand, you may not have any specially strong subjects but your records show a general satisfactory standard. Although not all subjects can be used directly in a job, they may have indirect value. A knowledge of history is not required for most jobs but if history is one of your good subjects you will have learned to remember facts and details. This is an ability that can be useful in many jobs.

Your school may have taught you skils, such as typing or technical drawing, which you can use in your work. You may be good at metalwork or cookery and look for a job where you can improve these skills. If you have had a part-time job on Saturdays or in the summer, think what you gained from it. If nothing else，you may have learned how to get to work on time，to follow rules and to get on with older workers. You may have learned to give correct change in a shop，for example. Just as important，you may become interested in a particular career you see from the inside in a part-time job.

Facing your weak points is also part of knowing yourself. You may be all thumbs when you handle tools；perhaps you are a poor speller or cannot add up a number of figures. It is better to face any weaknesses than to pretend they do not exist. Your school record，for instance，may not be too good，yet it is an important part of your background. You should not be apologetic（道歉的）about it but instead recognize that you will have a chance of a fresh start at work.

   A strong memory depends on the health and vitality（生命力）of your brain. They say that you can't teach an old dog new tricks，but when it comes to the brain，scientists have discovered that this old saying simply isn't true. 【小题1】

Give your brain a workout. Memory, like muscular strength, requires you to“use it or lose it”. The more you work out your brain, the better you' ll be able to process and remember information. 【小题2】

Don't skip the physical exercise. While mental exercise is important to brain health, that doesn't mean you never need to break a sweat. Physical exercise helps your brain stay sharp. It increases oxygen to your brain and reduces the risk of disorders that lead to memory loss.

Get enough sleep. There is a big difference between the amount of sleep you can get now and the amount you need to function at your best. 【小题3】

Keep stress in check. Stress is one of the brain's worst enemies. Over time, stress destroys brain cells. Studies have also linked stress to memory loss.

Have a laugh. 【小题4】 That holds true for the brain and the memory, as well as the body. Unlike emotional responses, which are limited to specific areas of the brain, laughter involves multiple regions across the whole brain.

【小题5】 Just as the body needs fuel, so does the brain. You probably already know that a diet based on fruits, vegetables, whole grains,“healthy”fats and lean protein will provide lots of health benefits, but such a diet can also improve memory. For brain health, though, it's not just what you eat — it's also what you don't eat.

As new students at an university in Boston，many of us were unfamiliar with the campus but consequently late for class. One professor，however，was particular intolerant of being late，making clear that no excuse would be acceptable. So when a girl student came to his class one morning later，we expected the worst results. Then the professor demands the reason for her coming late.“I was being waiting online to buy your new book，”she replied very nervously. While looked at the rest of the class，the professor asked，“Well，why was not the rest of you late？”