问题 选择题

一物体做匀变速直线运动,某时刻速度大小为2m/s,1s后速度大小变为8m/s,在这1s内物体的(  )

A.位移大小为5m

B.位移大小可能小于4m

C.加速度大小可能等于6

D.加速度大小可能大于6;

答案

BCD

末速度可能是8m/s或者-8m/s,匀变速直线运动的平均速度等于初末速度和的一半,即5m/s或者-3m/s,位移大小等于平均速度乘以时间,即5m或者3m,A错B对,加速度可求得6或者-10,CD都对

填空题
单项选择题

Are teens and young adults more narcissistic (自恋的) today than in the past That’s the view of a California researcher who studies (1) people.

In her new book, The Narcissism (2) : Living in the Age of Entitlement, psychologist Jean Twenge of San Diego State University and (3) W. Keith Campbell of the University of Georgia say research shows (4) young people today have "narcissistic traits" than in (5) generations. Such traits, Twenge says, include a very. (6) and inflated sense of self, which is (7) by a preoccupation with MySpace, Facebook and YouTube.

"We’ve been on this self-admiration cultural (8) for a long time," Twenge says. (9) Twenge’s take on today’s young people isn’t universal. Studies by other researchers, including Canadian (10) Dr. Kali of the University of Western Ontario, have used the same data but found (11) results. "They put a different (12) on it," Kali says.

Twenge’s studies have found more narcissistic traits and a (13) rate of increase among college students today, but Kali found that students’ narcissism was (14) greater in 2006 than in 1976. Twenge’s most recent paper studied the same data as Kali--more than 20 000 college students from 2002 to 2007. (15) researchers used the Narcissistic Personality Inventory to measure narcissistic (16) and findings by both have been (17) in peerreviewed journals.

Twenge’s book (18) just a month after The Mirror Effect : How Celebrity Narcissism Is Seducing America, a book co-written by behavioral (19) Drew Pinsky, (20) suggested that a celebrity-obsessed culture is causing more narcissism.

7()

A.criticized

B.illustrated

C.advocated

D.despised