Replacement of CaO by PbO in soda-lime glass results in .

A. denser glass with a higher refractive index
B. a softer glass with a lower melting point
C. glass with a deep blue color
D. a harder glass with a higher melting point
E. opaque glass

A. denser glass with a higher refractive index

Explanation:

The letter to grandmother explaining the health benefits of physical activity is discussed below.

Explanation:

Dear Grandmother,

I saw you eating a balanced diet and also taking all the health beneficiary but still, you feel tired and down and maybe that is because of missing Physical activity from your daily routine.

As you very well know a balanced diet is important for health the same as physical activity is also important for good health without the combination of a balanced diet and physical activity we can not become completely healthy and always end up getting tired.

There are so many benefits of physical activity such as,

decrease your chance of a heart attack.

maintain your weight better.

have a weaker blood cholesterol level.

reduce the chance of a variety of diabetes and some cancers,

So I request you to start doing physical activity from tomorrow onward.

Your grandson

XYZ