Q: What is the most commonly used source of energy in the world? Choices: - electricity - wind - water - oil A:
oil

(Question)
Q: Echinoderms have a unique system for gas exchange, nutrient circulation, and locomotion called the water vascular system. the system consists of a central ring canal and radial canals extending along each arm. water circulates through these structures allowing for gas, nutrient, and this? Choices: - water evaporation - nerve exchange - cell exchange - waste exchange A:
(Answer)
waste exchange

Ques: Q: What is the enclosed, fluid-filled membrane that surrounds and protects the fetus and is attached to the placenta? Choices: - epithelial sac - umbilical sac - womb - amniotic sac A:
Ans: amniotic sac

(Q).
Q: What part of an atom is electrically neutral? Choices: - protons - electrons - newtons - neutrons A:
(A).
neutrons

Ques:Q: What is a pure substance that cannot be separated into any other substances called? Choices: - light - Cells - Spears - element A:

Ans:element

Q: Microfilaments are mostly concentrated just beneath what? Choices: - the nucleus - the cell wall - the cytoplasm - the cell membrane A:
the cell membrane