What is the primary purpose of the digestive system?


Which of the following is a characteristic of bases?


What is the primary role of enzymes in the body?


Which of the following is an example of a chemical change?


What is the main function of the circulatory system?


Which of the following is a property of a solid?


What is the primary function of chlorophyll in plants?


Which of the following is an example of a physical change?


What is the main source of energy for the Earth?


Which gas is commonly used in balloons?