How seals can survive in polar climate where the temperature prevails below $0^{\circ} C$ ?

An area of soil is thoroughly wetted and allowed to drain until capillary movement of water stopped. The water contents of the soil will give an estimate of its

$A$ – The salt concentration is less than $5$ (parts per thousand) in inland waters.

$R$ – The salt concentration is $45 -50$ (parts per thousand) in the sea.

Consider the following four statements $(1-­4)$ about certain desert animals such as kangaroo rat.

$(1)$ They have dark colour and high rate of reproduction and excrete solid urine.

$(2)$ They do not drink water, breathe at a slow rate to conserve water and have their body covered with thick hairs.

$(3)$ They feed on dry seeds and do not require drinking water.

$(4)$ They excrete very concentrated urine and do not use water to regulate body temperature.

Which two of the above statements for such animals are true ?

Altitude sickness is managed by the body by