Gravity has been at the top of the science agenda since the start of Mars missions. In the earlier days of space travel, scientists tried to overcome the force of gravity so that a rocket could shoot __26__ Earth’s pull in order to land humans on the moon. Today, they are more interested in how reduced gravity affects the astronauts’ __27__ condition. Our bodies have evolved to exist within Earth’s gravity, not in the weightlessness of space or the microgravity of Mars. When on Earth, we have more fluids in our lower body because they are pulled down by Earth’s gravity. However, with the absence of gravity in the outer space, our body fluids redistribute, shifting toward the upper body and the head.  __28__ , the astronauts have swollen, puffy faces, very much resembling that of the round-headed Charlie Brown in the famous comic strip. This “Charlie Brown effect” will be more  __29__ when the astronauts go on their Mars missions, which will take about three years to complete, much longer than missions to the moon. Moreover, the effect is often  __30__ space motion sickness, headaches, and nausea. Such a syndrome is considered the top health risk for the astronauts, and scientists are still trying to figure out how it may be prevented.

       Ferris wheels are popular and beloved by everyone from small to big attraction. Children sitting in baskets are lifted  __31__ into the sky by an enormous wheel. The first Ferris wheel, named after its American inventor, Gale Ferris,  __32__ 130 years old in 2023. The Ferris wheel was seen and ridden by people visiting the world’s Columbian Exposition in Chicago. It was 250 feet  __33__ diameter, which was six times taller than any wheel at that time. It took 20 minutes  __34__ that wheel to turn around once. Thrill seekers paid 50 cents to take a ride. Today, Ferris wheels are still the centerpiece of any amusement park. Children and adults alike love the view from the top and the scary sensation of dropping back to earth. To celebrate the Ferris wheel’s 130th birthday, the Illinois State Fair plans to erect another wheel, making  __35__ of 13 wheels being set up in one location.

        A bagel is a ring-shaped bread product made from yeasted wheat dough. It is first boiled for a short time in water and then baked. The result is a chewy and doughy interior with a brown and crispy exterior. It  __36__ a wide variety of flavors. People can add cheese, ham or jam to a bagel and eat it for breakfast or dessert. It is a popular product in North America and Europe, especially in major cities with large Jewish populations. Jewish people have been  __37__ producing the first bagels since the 19th century, which have long been connected with Jewish traditions. During the Sabbath, cooking was prohibited as a rule. Therefore, many Jewish families would make bagels ready beforehand so that  __38__ the Sabbath was over, they could be baked quickly and consumed. The basic roll-with-a-hole design is hundreds of years old and has practical advantages like providing a  __39__ baking of the dough. The hole can be used to thread strings,  __40__ for easier handling and more convenient for vendor displays.