It would be nice if eating a particular food could magically protect you against all the boring illnesses.It's not that simple,of course.Hard washing remains your best defense against picking up illnesses,and sleep is a strong defense too.But what you eat does play an important part.Though it isn't because of just one or two foods,what you eat in your daily diet has an effect on how weak or strong your immunity（免疫力） is.
We'd better eat fruits and vegetables every day.They contain key vitamins needed in the immune system.For example,Vitamin C and A in foods help immune system work well to keep us healthy.Remember that eating the actual fruit or veggie is better than eating single-vitamin supplements （补品）.
Getting too little protein（蛋白质）can weaken your immune system.Protein-rich foods supply the amino acids （氨基酸） you need to build important proteins in the body.Animal foods like beef and pork also contain zinc （锌），which your body uses to make t-cells.
Fermented foods are foods that are naturally protected by bacteria（细菌），and they're good for the micro biome（微生物）.That's the name for the bacteria that live in your stomach,where a lot of cells in immunity actually live.Fermented foods like yogurt help beneficial bacteria develop fast in the stomach,leaving less room for harmful bacteria.



What does paragraph 1 mainly tell us？ ______

A. Hand washing is necessary.
B. Illnesses make people bored.
C. More sleep does good to health.
D. Immunity has much to do with your diet.

Why does the writer suggest we eat fruits and vegetables every day？ ______

A. They are rich in vitamins we need.
B. Vitamin A is helpful for immunity.
C. Fruits supply our body with Vitamin C only.
D. Eating single-vitamin foods does little good.

What can we infer from paragraph 3？ ______

A. Amino acids can help to make t-cells.
B. Healthy body needs plenty of protein.
C. The immune system can be hurt easily.
D. We should eat animal foods as many as possible.

What is the main idea of the text？ ______

A. Different foods have different uses.
B. Fruits and vegetables keep us healthy.
C. Many illness do harm to the immunity.
D. Proper daily diet protects our immune system.