Which one of the following is a human modified environment ?(1) Artificial lake(2) Sanctuaries(3) Crop fields(4) Dams

To determine which one of the options is a human modified environment, let's analyze each choice step by step:

1. Artificial lake: An artificial lake is created by humans for various purposes such as irrigation, water supply, or recreation. It involves the construction of a dam or reservoir to store water. Therefore, an artificial lake is indeed a human modified environment.

2. Sanctuaries: Sanctuaries are areas set aside for the protection and conservation of wildlife and their habitats. While humans may establish and manage sanctuaries, they are primarily intended to preserve natural ecosystems rather than modify them. Therefore, sanctuaries are not considered human modified environments.

3. Crop fields: Crop fields are areas where agricultural activities take place, involving the cultivation of crops for food production. Humans modify the natural landscape by clearing land, preparing the soil, and planting crops. Therefore, crop fields are human modified environments.

4. Dams: Dams are structures built across rivers or streams to control water flow, generate electricity, or provide water for various purposes. The construction of dams involves altering the natural course of water bodies, which makes them human modified environments.

In conclusion, the options (1) Artificial lake, (3) Crop fields, and (4) Dams are all human modified environments.