Answer the following question given this paragraph: Rainwater absorbs carbon dioxide (CO 2 ) as it falls. The CO 2 combines with water to form carbonic acid. The slightly acidic water is especially good at dissolving the rock limestone. Groundwater creates landforms by dissolving away rock. Q: Rainwater absorbs carbon dioxide (co 2 ) as it falls. the co 2 combines with water to form what? A:
OPTIONS:
- carbon monoxide
- nitrate acid
- methane gas
- carbonic acid

Answer: carbonic acid

Answer the following question given this paragraph: Homeobox genes are involved in the regulation of genes important to development. They encode transcription factors. Q: What types of genes encode transcription factors? A:
OPTIONS:
- glycosyl transferases
- isozyme genes
- rohail genes
- homeobox genes

Answer: homeobox genes

Answer the following question given this paragraph: The organs that make up the cardiovascular system are the heart and a network of blood vessels that run throughout the body. The blood in the cardiovascular system is a liquid connective tissue. Figure below shows the heart and major vessels through which blood flows in the system. The heart is basically a pump that keeps blood moving through the blood vessels. Q: The heart and a network of blood vessels that run throughout the body make up what organ system? A:
OPTIONS:
- lymphatic system
- respiratory system
- immune system
- cardiovascular system

Answer:
cardiovascular system