if the light coming from a distant object produces a bright line emission spectrum, what kind of object is it

According to the tide table below what time of day will the highest tide occur?

What are chlorofluorocarbons and what impact do they have on the atmosphere?

In a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina. what should be the radius of curvature of the cornea such that the image of an object 40.0 cm from the cornea’s vertex is focused on the retina?