There are several types of abnormal curvatures of the spinal column. Some of them are exaggerations of the normal curve. Kyphosis is an exaggeration of a curve that gives the person a hunchbacked appearance. You sometimes see this hump in elderly women with osteoporosis. Which normal curve is exaggerated in kyphosis

answer; both surfaces of the membrane are nonpermeable

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.