Suggest some reasons for heartwood being preferred to sapwood for making furniture?

Which of these resources is used worldwide to make construction products, pottery, and porcelain

Will someone me with this.. specialized cells which perform a particular function form: tissues organs or organism

1. watermelon, papaya, oranges, bananas, and lemons are included in this food group. vitamin c 2. you need 6 or more servings of this food group each day vitamins d and a 3. found in fruit and keeps blood vessels healthy calcium 4. vitamins found in milk bread and grain 5. a mineral that strengthens bones fruit