Concept:Groundwater is a limited resource. Wells dry up when water is used faster than it is replaced or when rainwater cannot reach the ground.
Explanation:Option (A) is false. Even if taps are available, people may still use wells. The main problem is overuse and lack of recharge.
Option (B) is correct. Using electric motors to pump groundwater rapidly lowers the water table, causing wells to dry up.
Option (C) is correct. Covering soil with cement or coal tar prevents rainwater from seeping into the ground. This stops the natural refilling of groundwater.
Option (D) is correct. Lakes and ponds used to collect rainwater and help recharge groundwater. When they are replaced by buildings, the water table does not get replenished.
Thus, the correct reasons are B, C, and D.
Answer:B. B, C and D