Polar molecules i believe
Answer:
The membrane is selectively permeable because substances do not cross it indiscriminately.
Explanation:
the answer is the ratio is off
1. Arteries : Carry's blood away from the heart.
2. Veins : Carry's blood back to the heart.
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3. Capillaries : exchange of materials and gases between the cell and vessel takes place here.</span>
Because they have flowers which attract pollinators