Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Microscopes, tools that you may get to use in your class, are some of the most important tools in biology ( Figure Microscopy is the study of small objects using microscopes. Look at your fingertips. Before microscopes were invented in 1595, the smallest things you could see on yourself were the tiny lines in your skin. But what else is hidden in your skin? Over four hundred years ago, two Dutch spectacle makers, Zaccharias Janssen and his son Hans, were experimenting with several lenses in a tube. They discovered that nearby objects appeared greatly enlarged, or magnified. This was the forerunner of the compound microscope and of the telescope. In 1665, Robert Hooke, an English natural scientist, used a microscope to zoom in on a piece of cork - the stuff that makes up the stoppers in wine bottles, which is made from tree bark. Inside of cork, he discovered tiny structures, which he called cells. It turns out that cells are the smallest structural unit of living organisms. This finding eventually led to the development of the theory that all living things are made of cells. Without microscopes, this discovery would not have been possible, and the cell theory would not have been developed. Hookes discovery of the cell set the stage for other scientists to discover other types of organisms. After Hooke, the "father of microscopy," Dutch scientist Antoine van Leeuwenhoek ( Figure 1.2) taught himself to make one of the first microscopes. In one of his early experiments, van Leeuwenhoek took a sample of scum from his own teeth and used his microscope to discover bacteria, the smallest living organism on the planet. Using microscopes, van Leeuwenhoek also discovered one-celled protists and sperm cells. Today, microscopes are used by all types of scientists, including cell biologists, microbiologists, virologists, forensic scientists, entomologists, taxonomists, and many other types. Antoine van Leeuwenhoek, a Dutch cloth merchant with a passion for microscopy. Some modern microscopes use light, as Hookes and van Leeuwenhoeks did. Others may use electron beams or sound waves. Researchers now use these four types of microscopes: 1. Light microscopes allow biologists to see small details of a specimen. Most of the microscopes used in schools and laboratories are light microscopes. Light microscopes use lenses, typically made of glass or plastic, to focus light either into the eye, a camera, or some other light detector. The most powerful light microscopes can make images up to 2,000 times larger. 2. Transmission electron microscopes (TEM) focus a beam of electrons through an object and can make an image up to two million times bigger, with a very clear image. 3. Scanning electron microscopes (SEM) allow scientists to find the shape and surface texture of extremely small objects, including a paperclip, a bedbug, or even an atom. These microscopes slide a beam of electrons across the surface of a specimen, producing detailed maps of the surface of objects. Magnification in a SEM can be controlled over a range from about 10 to 500,000 times. 4. Scanning acoustic microscopes use sound waves to scan a specimen. These microscopes are useful in biology and medical research. Scanning Electron Microscope at (5:04) Click image to the left or use the URL below. URL: 1. How is the electron beam focused? 2. What part of a specimen does a scanning electron microscope look at? 3. Why is it important that a specimen for an electron microscope be placed in a vacuum? Why is this step unnecessary for a light microscope?
who discovered single-celled protists?

You must have been troubled by when to say "I love you" because it is one of the greatest puzzles in our life. What if you say it first and your partner doesn't love you back? Or if they do say it but you don't feel they mean it? Being the first to declare your love can be never racking and risky and can leave you feeling as vulnerable as a turtle with no shell. But is the person who says it first really in a position of weakness? Doesn't it pay to hold back, play it cool and wait until the other half has shown their hand faster? "A really good relationship should be about being fair and being equal," says psychologist Sidney Crown. "But love is seldom equal." "All relationships go through power struggles but," he says, "if a love imbalance continues for years, the rot will set in." That feeling of "I've always loved you more" may be subverted (,) for a time, but it never goes away completely and it often emerges in squabbling . In love, at least, the silent, withholding type is not always the most powerful. "The strongest one in a relationship is often the person who feels confident enough to talk about their feelings," says educational psychologist Ingrid Collins. Psychosexual therapist Paula Hall agrees. "The one with the upper hand is often the person who takes the initiative." In fact, the person who says "I love you" first may also be the one who says "I'm bored with you' first." Hall believes that much depends on how "I love you" is said and the motivation of the person saying it. Is it said when they're drunk? Is it said before their partner flies off on holiday, and what it really means is "Please don' t be unfaithful to me" ? By saying "I love you", they are really saying "Do you love me?" If so, wouldn't it just be more honest to say that. Collins agrees that intention is everything. "It's not what is said, but how it's said. What it comes down to is the sincerity of the speaker."
What is the most important for you to consider when somebody say "I love you" to you?

It's no secret that doing good makes others happy - but did you know it can make you happy as well? According to a study, people participating in meaningful activities were happier and felt that their lives had more purpose than people who only engaged in pleasure-seeking behaviors. Try giving these four things to others to start your journey to a happier and healthier lifestyle. 1. Your Time With a busy life, it can be hard to find any time to give away. However, volunteering your time has great benefits, including making new friends and connections, learning new skills and even advancing your career. According to a paper about the link between health and volunteering, volunteering is connected with lower instances of depression and reduces the risk of dying by 22 percent. 2. Your Attention Most of us think we're good listeners, but according to psychologist Paul Donoghue, most people are aware that others don't listen as well as they could. In addition, they're not fully aware that they themselves aren't listening. When practicing mindfulness meditation , you focus on what you experience in the moment and let your thoughts and emotions pass through without judgment. Did you know that giving someone your undivided attention helps you also? When done well, active listening strengthens your focus-which is a major part of good meditation. 3. Your Compassion The psychological meaning of compassion is the ability to understand another person's emotional state. Compassion differs from empathy in that those who experience compassion not only put themselves in another person's shoes, but also want to reduce that person's suffering. A brain-imaging study showed that the brain's pleasure centers are equally active when we give money to the poor as when we receive money ourselves. 4. Your Money According to an experiment, those who spend money on other people are significantly happier than those who spend the same quantity of money on themselves. Whether or not you can offer other gifts, donating money helps make real change happen. It represents time spent, compassion and careful attention to the needs of others.

Which of the four gifts matters most according to the author?