Red blood cells have cell membranes that allow water, oxygen, carbon dioxide and glucose to pass through. all other materials are blocked from entering. this makes the membrane
a. perforated.
b. semi-permeable.
c. non-conductive.
d. permeable.

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Every early childhood education program should develop a

You and a group of friends are spending your vacation hiking through the mountains. it is cold in the mountains. you will be expending a lot of energy while hiking and you will need plenty of energy to keep you warm. you should pack foods high in to provide the most energy or kilocalories per gram of food. a) carbohydrates b) lipids (fats) c) proteins d) sugars