Lean women with a BMI less than 20 have an increased risks of preterm delivery, and deliver- ing a low-birth weight infant. The correct option among all the options that are given in the question is the first option or option "a". Similarly it is not good to gain excess weight while in the pregnancy stage, as the baby might grow at a larger proportion that required.
The air begins to rise into the atmosphere. When air rises, it cools down and condenses into precipitation and clouds. This is why an approaching low pressure system means an increased chance for clouds, rain, or snow. It is called "low pressure" because as air rises, the air pressure is lower at the surface.
The notable
hardness of bone is attributed to the presence of inorganic hydroxyapatites.
Due to the calcium salts deposited in it, resulting to the hardness. The
abnormal hardness of bone, which allows it
to resist the compression.