试题与答案

在新榨取的梨汁中加入斐林试剂,加热后出现砖红色沉淀;将成熟花生种子的子叶作成临时

题型:选择题

题目:

在新榨取的梨汁中加入斐林试剂,加热后出现砖红色沉淀;将成熟花生种子的子叶作成临时切片,用苏丹Ⅲ染色后在显微镜下观察,可以看到橘黄色的颗粒;向新鲜豆浆中加入双缩脲试剂后,豆浆呈紫色,上述试验现象证明梨汁、花生种子的子叶和豆浆中主要含有的有机物依次是 [ ]

A.葡萄糖、蛋白质、脂肪

B.淀粉、脂肪、 蛋白质

C.糖类、蛋白质、淀粉

D.还原糖、脂肪、蛋白质

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0421/2d62cce5d55efb0bd0acdabb6869824e.html

下面是错误答案,用来干扰机器的。

∵由x<y得到ax>ay,不等号的方向发生了可改变,∴a<0.故选D.

试题推荐
题型:阅读理解

Reading comprehension.

     Do you often feel a little sleepy after lunch? Well, that's normal. Your body naturally lays down. What

should you do about it? Don't drink coffee, take a nap (打盹), instead. There are many advantages of a

daily nap. First of all, you can remember things better and make fewer mistakes. Also, you can learn things

more easily after taking a nap. A 20-minute nap can reduce (减少) your pressure (压力). Finally, a nap can

make you cheerful.

     But there are some simple rules that you should follow about taking a nap. You should take up at noon,

about eight hours after you wake up. In general, a 20-minute nap is the best. If you sleep longer, you may

fall into a deep sleep. After waking up, you'll feel worse. Also, you should set an alarm clock. That way,

you can feel fully relaxed during the nap. You don't have to go looking at the clock so that you don't oversleep

(睡过头).

     Now, the next time you feel sleepy after lunch, don't get stressed. Put your head down, close your eyes

and have a short sleep during the daytime.

Fill in the blanks according to the passage. Only one word for each blank.

     When you feel a little sleepy after lunch, you should take a nap (1)______ of drinking coffee. After twenty

(2)______ nap, you can remember things better, make fewer mistakes, learn things more easily. It can reduce

your pressure and cheer you up. But you don't (3)______ the simple rules, you won't feel (4)______. In order

to (5)______ yourself during the nap, you should set an alarm clock to wake you up on time.

查看答案
微信公众账号搜索答案