Questions

Water has the maximum density at 4oC. So at this temperature, it sinks down to bottom and stays here. If it cools further, it will become less dense and move up. So while the upper layers can cool enough to form ice, the bottom layers remain as water at  4oC .  

Therefore, (C) is correct.

Both the floor and the carpet have the same temperature as both are exposed to the same atmosphere. But the former conducts away the heat from the feet better than the carpet as the latter is a non-conductor. So the feet losing more heat, the floor appears cooler to the feet.

Military Staffs normally follow four steps when preparing an effective briefing. They are:

1. Plan — analyze the situation and prepare a briefing outline.

2. Prepare — collect information and construct the briefing.

3. Execute — deliver the briefing.

4. Assess — follow up as required.