题干

2017年4月26日,我国首艘国产航母001A型航母成功下水,标志着我国自主设计建造航空母舰取得重大阶段性成果,可以搭载40﹣45架歼型舰载机.下列说法正确的是(   )

A:当舰载机静止在航母上时,航母受到的浮力与它们的总重力大小相等

B:当舰载机飞离航母时,航母将上浮,航母受到的浮力将变大

C:当舰载机降落在航母上时,航母将下沉,航母受到的浮力将变小

D:不论舰载机静止在航母上,还是离开航母,航母受到的浮力大小都不变

上一题 下一题 0.0难度 选择题 更新时间:2018-02-13 10:01:57

答案(点此获取答案解析)

A

同类题1

阅读理解

    “Educational researchers, political scientists and economists are increasingly interested in the characteristics and skills that parents, teachers and schools should foster in children to increase chances of success later in life,” said lead author Marion Spengler, PhD of the University of Tubingen.” Our research found that specific behaviors in high school have long-lasting effects for one's later life.”

    Spengler and her co-authors analyzed data collected by the American Institutes for Research from 346, 660 U. S. high school students in 1960, along with follow-up data from 81,912 of those students 11 years later and 1,952 of them 50 years later. The initial high school phase measured a variety of student behaviors and attitudes as well as personality characteristics, cognitive abilities, parental socioeconomic status and demographic(人口统计的)factors. The follow-up surveys measured overall educational attainment, income and occupational prestige(声望).

    Being a responsible student, showing an interest in school and having fewer problems with reading and writing were all significantly associated with greater educational attainment and finding a more prestigious job both 11 years and 50 years after high school. These factors were also all associated with higher income at the 50-year mark. Most effects remained even when researchers controlled parental socioeconomic status, cognitive aibility and other broad personality characteristics such as conscientiousness.

    While the findings weren't necessarily surprising, Spengler noted how reliably specific behaviors people showed in school were able to predict later success.

    Further analysis of the data suggested that much of the effect could be explained by overall educational achievements, according to Spengler.

    “Student characteristics and behaviors were rewarded in high school and led to higher educational attainment, which in turn was related to greater occupational prestige and income later in life,” she said. “This study highlights the possibility that certain behaviors at crucial periods could have long-term consequences for a person's life.”