题干

稀土有工业“黄金”之称,由于其具有优良的光电磁等物理特性,可以大幅度提高坦克、飞机、导弹等的战术性能。铈是一种稀土元素,它在元素周期表中的信息如图所示,下列有关说法错误的是(    )

A:铈的相对原子质量是140.1g

B:铈原子的核电荷数是58

C:铈元素符号是Ce

D:在化学反应中,铈原子一般失去电子

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答案(点此获取答案解析)

A

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阅读理解

    When kids believe they can achieve success in math and reading, they are more likely to achieve high test scores in those subjects, new research suggests.

    Researchers used one US data set (1,354 American children) and one UK data set (13,901 British children) to measure self-concept and standardized assessments of early and later academic achievement. Self-concept is how students perceive(感知)their abilities to succeed on academic tasks. The data involved youth aged 5 to 18.

    The study considered children's earlier achievement and their characteristics and backgrounds, including birth weight, race, gender, age, and their mother's education.

    The researchers found that children's self-concept of their ability in math predicted later math achievement, while their self-concept of their ability in reading predicted later reading achievement.

    The finding suggests that the links between self-concept of ability and later achievement are specific to areas; that is, there is a link from students' self-concept about reading to reading achievement, and from students' self-concept about math to math achievement.

     “It is not unusual to see standardized measures of achievement predict achievement later in schooling, but it shows that there is more to understand.” says study coauthor Pamela Davis-Kean.

    The research also showed that success was not limited to students who perform at the top levels.

     “It involves in students with different levels of achievement in math and reading,” says Maria Ines Susperreguy, an assistant professor at Pontificia Universidad Catolica de Chile, who led the study. “Even the lowest-performing students who had a more positive view of their math and reading abilities had higher levels of achievement in math and reading.”

    Researchers say they don't know what parents or students did to create these beliefs, but it's an issue they will research further.