First of all，this skin is actually a protein membrane(膜)-in fact，it's two layers of membranes，an inner one and an outer one.Their purpose is to protect the egg from bacterial attacks.(A yolk-the yellow part of an egg-is also covered in a clear membrane，but you're less likely to notice it.)

　　As you can see from the diagram above，an egg is not made up of just the yolk and whites.There's a whole lot more going on in there.We're certain，for example，that you've come across the strange white string，also known as the chalazae(卵黄系带)，when breaking an egg.

　　So how can you cook your eggs to make the inner membrane less apparent？It mostly depends on how you cook the eggs.

　　If you're looking to fully cooking your hard­boiled eggs-not soft­boiled one，or somewhere in between-there are a couple of things you should know.First，don't use the freshest eggs.Fresh egg whites bond more easily to the inner membrane than older eggs do，and this is what we're trying to avoid.And second，understand that according to the seasoned recipe and food tester Kenji，there is no simple method to avoid that membrane.But starting the eggs off in a pot of hot water (vs.cold water) will seriously improve your chances to easily peel away that inner membrane.

　　And if you find yourself peeling the skin and shell away from the egg，just remember that those barriers are

　　what protected the egg before it made its way to your kitchen.

1.What does the underlined word "intractable" in Paragraph 1 mean?

A.Meaningful. B.Flexible.

C.Practical. D.Challenging.

2.Which statement may the author agree with?

A.Membranes are typical of egg whites.

B.Membranes act as protectors of eggs.

C.The inner structure of eggs is changing daily.

D.The chalazae can only be seen in certain eggs.

3.What can be inferred from the last but one paragraph?