问题 单项选择题

评价预防接种效果的免疫学指标是()

A.抗体阳转率、抗体平均滴度

B.标化率、续发率

C.引入率、抗体阳转率

D.有效率、抗体平均滴度

E.保护率、效果指数

答案

参考答案:A

解析:免疫效果评价主要指标为接种后人群抗体阳转率、抗体平均滴度和抗体持续时间。疫苗保护率和疫苗效果指数为流行病学效果评价指标。

开放性试题
阅读理解

阅读理解。

     People live all over the world. They live on land that is low. They live on land that is high. Some live

 near the oceans. Others live far from the oceans.

      Earth has many different kinds of lands.  In some places, the land is flat.  Flat lands are called plains.

      Some parts of Earth have hills. Hills are higher than the land around them. But hills are lower than

 mountains. Did you ever try to ride your bicycle up a hill? Some parts of Earth touch oceans. These parts

  are called coasts. Some lands have water all around them. These lands are called islands.

      Earth has many different bodies of water, too. You know about the oceans. There are very large

 bodies of water.  The water in the oceans is salty. There are also smaller bodies of water called lakes.

 Lakes have land all around them. Rivers carry water from the land. They are long bodies of running water.

  The water in rivers is not salty, Most lakes do not have salty water, either.

 1. People live on _________l ands.

    A. high and salty    

    B. low and high

    C. low and salty      

    D. salty and flat

2. Hills are higher than _________and lower than

    A. mountains, the land

    B. mountains; lakes

    C. the land; mountains

    D. lakes; islands

3. Some lands with water around them are called___________.

    A. hills          

    B. mountains

    C. flats          

     D. islands

4. What's the meaning of the underlined word "coasts' ? It means"_________ " in Chinese.

5. According to (根据) the passage, which sentence is TRUE?

    A. The water in rivers and lakes is salty.

    B. The water in oceans and all lakes is salty.

    C. The water in oceans and some lakes is salty.

    D. The water in oceans and rivers is salty.