What is the missing first step of the following process: - The glucose and oxygen create carbon dioxide - The cells release energy - The cells don't have enough oxygen to repeat this - The cells obtain more oxygen from the air - The cells repeat this process.
Ans: Cells obtain glucose and oxygen

What is the missing first step of the following process: - Water seeps into the remains - Minerals dissolved in the water form crystals - Crystalized minerals cause the remains to harden - The minerals form a fossil.
Ans: An organism dies

What is the missing first step of the following process: - Some is reflected back into space - The rest of the energy is absorbed by land and oceans, heating the Earth - Heat radiates from Earth to space - Some of this heat is trapped by greenhouse gases in the atmosphere - Human activities such as burning fuel are increasing the amount of greenhouses gases - This causes more heat radiation to stay trapped in our atmosphere - The Earth's temperature rises -
Ans: Solar radiation reaches Earth's atmosphere

What is the missing first step of the following process: - The pollution negatively affects the water quality - The pollution negatively affects the health of plants and animals - The plants and animals have shorter, less healthy lives - The plants and animals do not reproduce very well - The number of plants and animals decreases over time - The quality of water gets worse and worse as there are no plants or animals to clean it - Eventually there is nothing living in the water and it is unusable -
Ans: Pollution enters natural water sources such as rivers and lakes