短文填空。

     Do you often have a cold, headache or backache? If your answer is "Yes", your __1__ has a problem. 

  Healthy food is __2__ for our health. Tofu is a healthy food. It's __3__ a traditional (传统的) Chinese

  food. We often eat it in China. Now many people in other __4__ think tofu is good for health, too. They

  also like __5__  it.

     Milk is __6__ kind of healthy food. You __7__ drink one or two glass of milk every day. Vegetables

  are important, too. You should eat __8__ of them.

     Of course, it's important to eat a balanced diet (均衡饮食). You need some __9__ such as pork,

 chicken or beef every day. But you shouldn't eat too __10__ of them.

病毒持续感染属于

A．生理性免疫防御
B．生理性免疫稳定
C．免疫防御作用过高
D．免疫监视功能失调
E．免疫稳定功能失调