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.

which line shows the main idea of the bolded paragraph?

a. science has given humans many amazing devices
b. we know so much about our bodies and how to stay healthy
c. sometimes scientists fail to find all the answers
d. one mystery that still remains unsolved is why we yawn

Which tone best fits a business letter

Part a which statement best describes a central idea in this narrative? in times of tragedy, it is difficult to determine how best to be of service. in times of crisis, people prefer to be alone. young people tend to look to older people to take action in times of tragedy. when people publicly commit to being of service, they are more likely to follow through. part b which detail from the text best to shape the central idea in part a? "'i thought you might have too much going on already. i saw everyone post online.' martin said, 'i don’t think anyone wanted to be in the way today, so i’m glad you came.'" "finally, he said, 'i don’t know what to do. i guess i should tell him to let me know if he needs anything, but that doesn’t feel like enough.'" "he wondered how many people would actually show up to out and how many would simply hope that enough others did." "he explained to her that martin’s mom had died, and told her how he felt about his friend’s loss. 'what do you plan to do for him? ' his mother asked."

Read the claim. human bodies have developed over time to support a vegetarian diet. which sentence provides the best supporting evidence for the claim? because humans have evolved over millions of years, it makes sense that our diet has evolved as well. i can feel the negative effects of meat and its excess vitamins when i consume meat products. the length of human intestines is better suited to digest food derived from plants than to digest meat. human taste buds have matured throughout history in a way that makes people crave the flavor of meat.