Insensible fluid loss refers to water lost through:
(a) perspiration only
(b) feces only
(c) perspiration and expiration
(d) urine and feces

C. Perspiration and expiration.

Explanation – Insensible water loss is the type of loss which can't be felt like loss through perspiration or sweat and evaporation loss from the respiratory tract which is expiration. Sensible water loss is mainly urine which is released under our senses like see, feel and measure.

Insensible water loss is around 500-650ml/day according to some sources. There are certain factor that affects insensible water loss and are : temperature of the environment, humidity, altitude etc.  

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.