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Official 30 Lec 2
Question 5 of 6
What is the function of the spongy tissue in the bones of a female bird?

A.

In makes the bird more comfortable while sitting on her eggs for long periods of time.

B.

In enables female birds to lay more eggs.

C.

It strengthens the bird's bones just before she lays her eggs.

D.

It serves as a source of calcium for eggshells.

正确答案:D

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