问题 单项选择题

下列说法错误的是:

A.蓝藻对地球表面从无氧变成有氧的大气环境起了巨大作用 

B.植物光合作用主要在细胞的线粒体中进行 

C.呼吸作用分为有氧呼吸和无氧呼吸两种类型 

D.种子植物是地球表面绿色的主体

答案

参考答案:B

解析:解析 叶绿体是绿色植物进行光合作用的场所。没有叶绿体,绿色植物就不能进行光合作用。故本题答案选B。 考点:科技常识

阅读理解

阅读理解。

     Plants are very important living things. Life could not go on if there were no plants. This is because

  plants can make food from air, water and sunlight.  Animals and men can't  make food from air, water

 and sunlight. Animals get their food by eating plants and other animals.  Therefore, animals and men

 need  plants in order to live.  This is the reason why we find so many plants around us.

      If you look carefully at the plants around you, you will find that there are many kinds of plants. Some

 plants are large while others are small. Most plants are green.

      Some plants have many small leaves.  Others have only a few.  There are many kinds of leaves.

 Leaves are of different shapes and colors.

      Leaves are also different in other ways.  Some leaves have long thin parts at the end, we call them

 leaf stalks, some have short leaf stalks, others even have no leaf stalks.  The leaf edges (边缘)  are also

 different. Some leaves have smooth (平滑) edges. Some have wave-shaped edges. Others have edges

 like the teeth of a saw (据子).

1. Which of the following shows the right relation (关系) according to the first paragraph?

    

2. Plants are important because _____.

    A. we need to eat plants every day

    B. men can't live without plants 

    C. we can see so many plants around us

    D. animals eat plants as their only food

3. We know from the passage that _____.

    A. all leaves have leaf stalks

    B. all leaves have smooth edges

    C. plants are different in shapes but have the same color

    D. leaves are different in shapes and colors

4. The underlined words "leaf stalks" in the last paragraph mean _____.

    A. 叶边        

    B. 叶纹        

    C. 叶柄    

    D. 叶尖

5. The main idea of the passage  is  _____.           

    A. how plants help men and animals

    B. plants are important and they are quite different

    C. plants are more important than air, water and sunlight

    D. why we find so many plants around us

单项选择题