Yellowstone National Park is the U.S. States of Wyoming, Idaho and Montana. It became the first National Park in 1872. There are geysers and hot springs at Yellowstone. There are also many animals at Yellowstone. There are elk, bison, sheep, grizzly, black bears, moose, coyotes, and more.
More than 3 million people visit Yellowstone National Park year. During the winter, visitors can ski or go snowmobiling there. There are also snow coaches that give tours. Visitors can see steam (vapor water) come from the geysers. During other seasons, visitors can go boating or fishing. People can ride horses there. There are nature trails and tours. Most visitors want to see Old Faithful, a very predictable geyser at Yellowstone Visitors can check a schedule to see the exact time that Old Faithful is going to erupt. There are many other geysers and boiling springs in the area. Great Fountain Geyser erupts every 11 hours. Excelsior Geyser produces 4,000 gallons of boiling water each minute! Boiling water is 100 degrees Celsius, or 212 degrees Fahrenheit – that’s very hot! People also like to see the Grand Prismatic Spring. It is the largest hot spring in the park. It has many beautiful colors. The beautiful colors are caused by bacteria in the water. These are forms of life that have only one cell. Different bacteria live in different water temperatures. Visiting Yellowstone National Park can be a week – long vacation or more. It is beautiful and there are activities for everyone.
What causes colors in the springs?
When we are young, we learn that tigers and sharks are dangerous animals. We might be scared of them because they are big and powerful. As we get older, however, we learn that sometimes the most dangerous animals are also the smallest animals. In fact, the animal that kills the most people every year is one that you have probably killed yourself many times: the mosquito.
While it may seem that all mosquitoes are biters, this is not actually the case. Male mosquitoes eat plant nectar. One the other hand, female mosquitoes feed on animal blood. They need this blood to live and produce eggs. When a female mosquito bites a human being, it transmits a small amount of saliva into the blood. The saliva may or may not contain a deadly disease. The result of the bite can be as minor as an itchy bump or as serious as death.
Because a mosquito can bite many people in the course of its life, it can carry diseases from one person to another very easily. Two of the most deadly diseases carried by mosquitoes are malaria and yellow fever. More than 700 million people become sick from these diseases every year. At least 2 million of these people will die from these diseases.
Many scientists are working on safer and better ways to kill mosquitoes, but so far, there is no sure way to protect everyone in the world from their deadly bites. Mosquito nests can be placed over beds to protect people against being bitten. These nets help people stay safe at night, but they do not kill any mosquitoes. Mosquitoes have many natural enemies like bats, birds, dragonflies, and certain kinds of fish. Bringing more of these animals into places where mosquitoes live might help to cut down the amount of mosquitoes in that area. This is a natural solution, but is does not always work very well. Mosquitoes can also be killed with poisons or sprays. Even though these sprays kill mosquitoes, they may also harm other plants or animals.
Although mosquitoes may not seem as scary as larger, more powerful animals, they are far more dangerous to human beings. But things are changing. It is highly likely that one day scientists will find a way to keep everyone safe from mosquitoes and the diseases they carry.
Which of the following best summarizes the information in paragraph 4?