问题 单项选择题

Ach使窦房结细胞自律性降低是通过

A.最大复极电位降低
B.阈电位水平下降
C.If电流增强
D.膜对K+通透性增大
E.Ca2+内流增强

答案

参考答案:D

阅读理解

阅读理解。

     Lily is a poor fourteen-year-old girl. Her parents died when she was little, and she now lives with her

 grandma. They are so poor that Lily's grandma has to recycle (回收) things on the street to make a living.

  She works hard to give Lily the things that she needs in life.

     One day, a man riding his bike very fast knocked Grandma down when she was walking on the street.

  Grandma was badly hurt and she had to be in bed for a long time. Lily was very sad, and she had to look

  after her grandmother and herself. After school, she did all the housework herself. And she also did the

 recycling to make some money on weekends. After doing this, she knew how nice Grandma was. It made

  her really appreciate what Grandma had been doing for her.

     Fortunately, Grandma got well a few months later. Lily made up her mind to be a doctor. She wants to

  help people who are in need and make a lot of money to help her grandma. She works hard because she

  knows it will not be easy to make her dream come true. And she will never give up. 

1. What's the story mainly about?

    A. An accident.

    B. A poor family's life.

    C. The importance of recycling.

    D. A poor but hard-working girl.

2. What do we learn about Lily's grandmother?

    A. She is funny.

    B. She is rich.

    C. She is strict with Lily.

    D. She is very kind to Lily.

3. Which of the following is true?

    A. Grandma can't walk any more.

    B. Grandma needed a long rest after the accident.

    C. Grandma got hurt in a car accident.

    D. Lily recycled things every day.

4. Why does Lily want to be a doctor?

    A. Because she hopes to help others.

    B. Because she wants to become rich.

    C. Because she hates recycling.

    D. Because she wants to leave her family.

5. What does the underlined word "appreciate" mean?

    A. 迷惑

    B. 怀疑

    C. 讨厌

    D. 感激

判断题