For each statement below, write true or false. __ 4. Some lakes are fed by karst springs which are like underground rivers emerging from the ground. __ 5. All springs have essentially the same temperature of water. __ 6. Geysers are hot springs that erupt at regular intervals.

4. True. Some lakes are indeed fed by karst springs, which are like underground rivers emerging from the ground. These springs occur in areas with soluble rocks such as limestone, where water has dissolved the rock, creating underground passages and caves. The water from these springs can feed into lakes.<br /><br />5. False. The temperature of springs can vary depending on the geology and hydrology of the area. Springs can be cold, warm, or hot, depending on the temperature of the underground water source.<br /><br />6. False. Geysers are hot springs that erupt at irregular intervals, not regular intervals. The eruptions occur when the pressure in the underground reservoir exceeds the pressure in the geyser's plumbing system, causing the hot water and steam to erupt. The intervals between eruptions can vary greatly, from minutes to years.