Explain the difference between the geoid and the surface of the earth?

770

---

Explain what time period can carbon-14 dates have?

829

---

Explain what did radon detection in arid areas can help to explore?

867

---

Explain the minimum depth needed for a feature to be considered a canyon?

751

---

Explain what ways can igneous rock form two ways?

820

---

Explain the difference between a canyon, gorge, and valley?

793

---

Explain how old is the earth?

778

---

Explain the mantle made of?

800

---

Explain how continental heat flow is produced?

841

---

Explain why does marble rarely contain fossils?

779

---

Explain worm feeds itself by sucking the blood of animals and humans.after feeding, the worm becomes fat and falls off?

1069

---

Explain what was the period of time two beat,s in hurts?

1015

---

Explain how the slides and specimens used as instructional resources?

1060

---

Explain which is better to grow plants in rock sand or soil?

974

---

Explain what happens when the cell membrane or plasma membrane ruptures or breaks down?

1131

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