1. brought in the clean air act in 1956
2. people in developing countries often do not have laws to protect the air that they breathe
b) prop roots
mangrove trees grow near the water edges where the soil is wet and muddy. they are often subjected to waves and flooding. as a mean of extra support, they develop pitchfork like roots from the lower nodules in addition to the original root system. these are called prop roots which go down in the soil and anchor themselves. they branch further by trapping sediments in order to provide additional support.
question: true or false most plants are c3 plants, because they use molecules of carbohydrate known as g3p in their photosynthesis process.