A glass test-tube filled with water is heated at its upper end. The water at the top boils, yet the water at the bottom stays cold. Which row gives the explanation for why the water at the bottom of the test-tube stays cold?
- Aglass: good thermal conductor; water: good thermal conductor
- Bglass: good thermal conductor; water: poor thermal conductor
- Cglass: poor thermal conductor; water: good thermal conductor
- Dglass: poor thermal conductor; water: poor thermal conductor