Questions

Yes, all the above given sentences have an interjection.

1. Hey ! is an interjection in the sentence , Hey!, where did I park my car? 

2. Well is an interjection in the sentence, Well!, that's a relief.

3. Oh! is an interjection in the sentence , Oh!, now I remember where i put my wallet.

Ichthyology is the branch of biology devoted to the study of fish.

It is also known as Fish science which includes bony fishes (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha).

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Pulmonary abscess is a type of liquefactive necrosis of the lung tissue. 

Hence, Localized area of pus formation in the lungs is Pulmonary abscess.

The nearest stars to Earth are in the Alpha Centauri triple-star system, about 4.37 light-years away. One of these stars, Proxima Centauri, is slightly closer, at 4.26 light-years.

Of all the stars closer than 15 light-years, only two are spectral type G, similar to our sun: Alpha Centauri A and Tau Ceti. The majority are M-type red dwarf stars.

Only nine of the stars in this area is bright enough to be seen by the naked human eye from Earth. These brightest stars include Alpha Centauri A and B, Sirius A, Epsilon Eridani, Procyon, 61 Cygni A and B, Epsilon Indi A and Tau Ceti.

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A Light-year is a distance that light travels in the vacuum in one Julian year (365.25 days).

The light-year is a unit of length used to express astronomical distances. It is about 9.5 trillion kilometers or 5.9 trillion miles.