C. To tell an interesting story. D. To present a research result.

　　D

　　It seems hard to watch someone yawn（打哈欠）and not to yawn ourselves. Even reading about yawning can make you do it. Now, a new study has found why yawning has such a powerful force.

　　Yawning when others yawn, the study suggests, is a sign of pity and a form of social connection. Kids don’t develop this deeply rooted behavior until around age four, the study found. Kids with autism （自闭症） are less likely to catch yawns. In the most serious cases, they never do. Yawning might help doctors to see whether the children are developing rightly. The work could also lead to a better understanding of the ways that people communicate and connect.

　　“Emotional infection seems to be a born thing that connects us together,” said Molly Helt, a graduate student in psychology at the University of Connecticut. “Yawning may be part of that.” Inspiration for her study came when she tried to get her own autistic son to clear his ears on an airplane. She repeatedly yawned at him, hoping he would yawn back. He never did.

　　“The fact that autistic kids don’t do it might mean they’re really missing out on that emotional connection with people around them, ” she said. “The biggest thing people try to figure out after birth is how we become humans and understand that humans have minds that are different from others’," she added. "Autistic people never seem to understand that.”

【河北省辛集中学2017-2018学年高二下学期第二次阶段考试英语试卷】相关文章：

★ 河南省安阳一中2016-2017学年高一上学期第二次阶段考试英语试题

★ 河北省保定市高阳中学2017-2017学年高一12月月考英语试题

★ 河北省容城中学2017-2017学年高一上学期期中考试英语试题

★ 甘肃省白银市会宁县第二中学2016-2017学年高一上学期期末考试英语试题（无答案）Word版

★ 河北省石家庄市2016-2017学年高二上学期期末考试英语试卷

★ 安徽省蚌埠市五中十二中2015届高三上学期期中考试英语试卷 Word版含答案

★ 湖南省怀化市怀化三中2017-2017学年高一上学期期中考试英语试题 Word版含答案

★ 河南师大附中2017-2017学年高一上学期期中考试英语试题

★ 河北省蔚县第一中学2017-2017学年高一上学期期中考试英语试题

★ 浙江省东阳中学2017-2018学年高二下学期期中考试英语试卷