题干

设某大学的女生体重y(单位:kg)与身高x(单位:cm)具有线性相关关系,根据一组样本数据(xi,yi)(i=1,2,…,n),用最小二乘法建立的回归方程为: y =0.85x﹣85.71,则下列结论中不正确的是(   )

A:y与x具有正的线性相关关系

B:回归直线过样本点的中心( x¯y¯

C:若该大学某女生身高为170cm,则可断定其体重必为58.79kg

D:若该大学某女生身高增加1cm,则其体重约增加0.85kg

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C

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阅读理解

    Traffic Light Reading is one of students' favorites! And it's so simple. Here's what to do: Take three pens in different colors, most suitably red, orange and green. But it's not too important as long as teachers and students are both clear on the colour code they're going to use.

    Students read a text, not worrying too much about how much they understand. Teachers can ask them to re-read when students are paying attention to vocabulary. Start by underlining the words that they understand completely (including names, numbers etc) in green.

    Then students re-read the text and underline the words that look familiar-they maybe know them but aren't too sure about them. You guessed it: in orange.

    Finally, students read the text a third time underlining the words they clearly don't understand in red. Sometimes teachers might want to set students a limit for how many red words they underline, telling them only to underline the words that they believe are seriously blocking their understanding of the text as a whole. Generally, however, students are pleasantly surprised by how few words are red and how many are green. Seeing their ability laid out in a visual way really helps to increase confidence.

    Once the whole text is underlined, teachers can give students a limit of 5, 10 or 15 words, depending on the length of the text, and tell them they're only allowed to look these words up in a dictionary. This helps them to recognize words that are actually getting in the way of their understanding of the text and words that they don't know but actually don't impact their whole understanding of the text.

    This is a useful activity that can be done with a printed text, in a Google Doc, on RealtimeBoard, or set as a homework task for some independent study.