The college entrance examination is just around the corner. Homework and tests will keep many of you up late at night, and you may plan to make up for your lost sleep during the weekends. {#blank#}1{#/blank#} is it useful? A study published in the journal Current Biology completely has changed {#blank#}2{#/blank#} people used to think. It shows that the habit of sleeping in on weekends doesn't fix the damage done by a lack of sleep during the week. Even {#blank#}3{#/blank#} (bad), it may damage your health.

D

With the completion of the Human Genome（基因组）Project more than 20 years ago, and the discovery of the double helix structure of DNA enjoying its 70th birthday last year, you might assume that we know how life works. Think again!

Evolution has a 4bn-year head start on us. However, several aspects of the standard picture of how life works-the idea of the genome as a blueprint, of genes as instructions for building an organism, of proteins as precisely tailored molecular（分子）machines and more-have wildly reduced the complexity of life. 

In the excellent book How Life Works, Philip Ball explorers the new biology, revealing life to be a far richer, more delicate affair than we have understood. Ball explains that life is a system of many levels-genes, proteins, cells, tissues, and body modules-each with its own rules and principles, so there is no unique place to look for an answer to it. 

Also, How Life Works is a much more appealing title than the overused question of "What is life?". We should be less concerned with what a thing is, and rather more focused on what a thing does. Defining a living thing implies an unchangeable ideal type, but this will run counter to the Darwinian principle that living things are four-dimensional, ever changing in time as well as space.

But it's an idea that is deeply rooted within our culture. Ball points out that we rely on metaphors（比喻）to explain and explore the complexities of life, but none suffice. We are taught that cells are machines, though no machine we have invented behaves like the simplest cell; that DNA is a code or a blueprint, though it is neither; that the brain is a computer, though no computer behaves like a brain at all.

Ball is a terrific writer, pumping out books on incredibly diverse subjects. There's a wealth of well-researched information in here, and some details that are a bit chewy for the lay reader. But the book serves as an essential introduction on our never-ending quest to understand life.

Strategies to Overcome Self-Doubt Once and For All

Being self-confident is not easy and not everyone can do it, but it doesn't need to be that difficult. {#blank#}1{#/blank#}

Going through life can be very challenging at times. When we were young, no one told us how hard it will be in the future but here we are {#blank#}2{#/blank#} And it is unpleasing and can kill your confidence levels if not controlled from the beginning.

We will all experience some self-doubt, which is natural. {#blank#}3{#/blank#} It happens to us during normal days or whenever we are going to start a new job, a new task, or a new relationship, anything new in life will make you self-doubt. This sort of feeling puts you into dark days when nothing seems to go right and you might feel like giving up, and that is the time to be strong.

 {#blank#}4{#/blank#} Self-doubt is when you are unsure about one or more aspects of yourself. For example, when starting a new job, you might feel inexperienced or might think that you are not fit enough for the job, and this is a prime example of self-doubt.

 {#blank#}5{#/blank#} Low-level of self-criticism is actually good for you. It motivates you and pushes you to be better in life, to become greater than yesterday. This type of feeling will push you to work harder and faster than before and will also increase your productivity, but it should be a low level of self-criticism. You don't want to punish yourself over things that are beyond your control.

A. We needn't take it seriously.

B. It's impossible for us to deal with it.

C. One of the big problems of adult life is having self-doubt,

D. Self-doubt isn't all that bad, let us tell you why.

E. Let's explore to find ways to remove self-doubt forever.

F. It will take long for us to solve this problem.

G. There are some people mistaking self-doubt for something else.

One teacher had two students. One of them had a positive vision while the other had the 1 one.

One day, the teacher 2 for a park with both the students and while wandering in the garden, they 3 a mango tree from which some ripe and juicy mangoes were 4 . On seeing this, the teacher thought to 5 both of his students. Then, he asked the first one, "My dear child, what do you think of this mango tree?"

The student answered instantly, "Teacher, in spite of people 6 this tree with stones, it gives us sweet and juicy mangoes. It does 7 but still it gives us fruits. I wish all human beings learn this important 8 from the mango tree-to share their 9 even if they have to suffer for this."

After that, the teacher asked the other student the same question. The student 10 answered, "Teacher, this mango tree is no good and will not give mangoes by itself but only when we hit it with stones and 11 . Therefore, we should hit it hard to get sweet mangoes from it. That is the only way to 12 these mangoes. It is also clear from this tree that in order to get good 13 from others, we need to be violent and only when we become violent, then and only then will we get 14 ."

The teacher was delighted with the answer given by the first student because he had an admirable vision and 15 the tree with positive vision.