سؤال 43

Leaves are thin as well as broad. What does being thin do for a leaf?

It lets the light shine right through the leaf to the ground below
It stops the leaf from getting too heavy for its stalk
It keeps the distance short for gases diffusing in and outپاسخ درست
It lets the leaf bend in the wind without tearing

توضیح

Diffusion is slow over long distances, so keeping every cell close to a surface means the gases a leaf exchanges never have far to travel. The look-alike answer about light passing through describes the clear covering of a leaf rather than its thinness, and light that passes straight through has not been used at all.

توضیح

ادامهٔ این آزمون