subject
English, 25.07.2019 23:20 jazzlashayy1487

science mysteries: why do people yawn?
science has given humans many amazing devices and useful bits of knowledge. we know so much about our bodies and how to stay healthy, for example. we also know how to make machines and devices that make life easy for us. scientists dedicate their lives to knowledge, but even with a lifetime commitment, sometimes scientists fail to find all the answers. one mystery that still remains unsolved is why we yawn—what makes us yawn and what purpose it serves.
recent studies suggest that we yawn when we get tired as a way to encourage our brains. the theory is that yawning cool the brain, allowing it to work more efficiently. according to webmd's article about these studies, when you yawn, your jaw muscles get stretched, increasing blood flow to your neck, face, and head. also a deep breath during the yawn forces spinal fluid and blood down from the brain. the cool air then cools down these fluids.
other scientists believe, however, that yawning is a form of communication. this theory attempts to explain why yawning seems to spread from person to person. this kind of behavior is called "contagious yawning" and carries with it a possible social message. scientists are not yet sure what exactly the message is, but they believe people who have more social empathy are more likely to start yawning when they see someone else yawning.
scientists will continue to investigate the mystery of the yawn. is it a leftover behavior from before humans had language? was it a "hey, i'm sleepy. let's go to sleep" message? or is it really just a way to keep our brains cool? while this behavior still is largely a mystery, one thing is certain: you are probably fighting the urge to yawn right about now.
which line shows the main idea of the bolded paragraph?
yawning is a form of communication
yawning seems to spread from person to person
scientists are not yet sure what exactly the message is
people who have more social empathy are more likely to start yawning

ansver
Answers: 1

Another question on English

question
English, 21.06.2019 22:40
What name was given to the western european christian church after the religious schism in 1054 ce?
Answers: 1
question
English, 21.06.2019 23:50
Which phrase from the article suggests a tone that is formal but subjective? a- "thirty-six inches long and sixteen inches wide" b- "loads of fun with it" c- "most generous and attractive" d- "must be new subscribers" one of the most generous and attractive offers ever made to washington boys and girls is announced today by the washington times circulation department. for a limited time, national capital youngsters who show enterprise and energy will be given disc wheel coaster wagons in return for a few hours of their time. each boy or girl who sends in to the circulation manager, room 242, the names and addresses of ten friends or relatives who agree to take the washington times for six months, will receive one of these wagons, which can be made a source of profit as well as unending enjoyment for youngsters. the boys and girls are merely asked to obtain the signatures of ten friends or relatives. no money is to be collected and no work is required. the washington times is the most popular and constantly growing newspaper in the national capital and it is easy and simple to obtain the required ten signatures. as soon as the signatures are verified, the disc wheel coaster wagon will be delivered to the energetic boy or girl. the disc wheel coaster wagon is thirty-six inches long and sixteen inches wide. the coaster is built exactly like a high-powered automobile. the disc wheels have rubber tires and true roller bearings. it runs as smoothly as an eight-cylinder automobile. it is built of the strongest wood and is equipped with a reliable hand brake, enabling the owner to stop in an instant. the tongue—usually the first thing about a wagon to break and render the wagon unserviceable—is so stout that a man can jump on it without breaking it. it is built for real boys and active girls and they are bound to have loads of fun with it. besides using the wagon for pleasure and going visiting, boys and girls can use it to make money, running—or riding—errands, delivering packages, wheeling marketing home, etc. the disc wheel coaster wagon is so strongly built that it will withstand the roughest usage to which it may be subjected and will last for years. every boy and girl who wants one of the attractive and most desirable disc wheel coaster wagons should start today to sign up the necessary ten relatives or friends as home delivery subscribers for the washington times for six months. bear in mind that the ten persons whose signatures you obtain must be new subscribers—that is, they must be persons who are not having the washington times delivered at their homes at present. here’s hoping every boy and girl in washington gets a disc wheel coaster wagon before many days.
Answers: 1
question
English, 22.06.2019 00:10
How now how now chop logic what is this proud and i you and i you not and yet not proud mistress minion you me no nor proud me no proud
Answers: 3
question
English, 22.06.2019 06:10
The playwright would be able to express __ but the painter likely would not
Answers: 2
You know the right answer?
science mysteries: why do people yawn?
science has given humans many amazing devices and use...
Questions
question
Health, 20.10.2020 22:01
question
Mathematics, 20.10.2020 22:01
question
Social Studies, 20.10.2020 22:01
question
English, 20.10.2020 22:01
question
Chemistry, 20.10.2020 22:01
question
Mathematics, 20.10.2020 22:01