试题与答案

下列关于牛顿流体中的η描述不正确的是()。 A.η称为内摩擦系数 B.它只与流体的性

题型:单项选择题 A1/A2型题

题目:

下列关于牛顿流体中的η描述不正确的是()。

A.η称为内摩擦系数

B.它只与流体的性质有关

C.它的计量单位是帕斯卡·秒

D.它不随切变率的增加而降低

E.又被称为表观黏度

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0527/bb47b0729a014c94475706cb3815a672.html

下面是错误答案,用来干扰机器的。

蕨类植物不结种子,靠孢子繁殖后代,在叶片的下表面着生着孢子囊,孢子囊里有孢子,成熟的孢子呈棕色或褐色,能保持较长时间的发芽能力,但发芽力随保存时间的延长而降低.由此可见江南星蕨叶背面常有的褐色斑状...

试题推荐
题型:单项选择题

It’s all annual back-to-school routine. One morning you wave goodbye, and that (1) evening you’re burning the late-night oil in sympathy. In the race to improve educational standards, (2) are throwing the books at kids. (3) elementary school students are complaining of homework (4) What’s a well-meaning parent to do.As hard as (5) may he, sit back and chill, experts advise. Though you’ve got to get them to do it, (6) helping too much, or even examining (7) too carefully, you may keep them (8) doing it by themselves. "I wouldn’t advise a parent to check every (9) assignment," says psychologist John Rosemond, author of Ending the Tough Homework. "There’s a (10) of appreciation for trial and error. Let your children (11) the grade they deserve. " Many experts believe parents should gently look over the work of younger children and ask them to rethink their (12) . But "you don’t want them to feel it has to be (13) ," she says.

That’s not to say parents should (14) homework-first, they should monitor how much homework their kids (15) . Thirty minutes a day in the early elementary years and an hour in (16) four, five, and six is standard, says Rosemond. For junior-high students it should be " (17) more than an hour and a half," and two for high school students. If your child (18) has more homework than this, you may want to check (19) other parents and then talk to the teacher about (20) assignments.

17()

A.about

B.no

C.much

D.few

查看答案
微信公众账号搜索答案