Environmental impact assessment refers to what impact the plan or project will have on the atmosphere, water, soil, organisms and the environmental system composed of them when the development plan or construction project is drawn up, and the results of these impacts will again affect human health and life Investigations, predictions and evaluations of the environment, the natural environment, and the economic, cultural, and historical environment, and measures and measures to prevent or reduce environmental pollution and damage based on this. According to the above definitions, Which of the following behaviors that belong to environmental impact assessment are:. ['Before constructing a polluted water treatment plant in a city, ask experts to investigate, predict and evaluate the daily sewage treatment capacity of the plant based on the city size.', 'After a viaduct was built in a city, residents of several nearby buildings reported that the bridge had severely affected daylighting, and the city government organized relevant departments to evaluate to determine how to deal with it.', 'Before treating an ancient river in a city, ask experts to research the history of the river to develop tourism resources.', 'Before constructing an airport in a city, predict aircraft noise and make regulatory recommendations for land use around the airport.']