Answer: A. Paris is an old city, but some is even more ancient.
Explanation:
A is a compound sentence because the there are two complete sentences in the sentence. “Paris is an old city” is a complete sentence. “Some is even more ancient” is another full sentence. If there are two or more complete sentence separated by a conjunction, then It is a compound sentence. B is not a compound sentence, because there is only one complete sentence.
Answer:
--- Radius
--- Height
Explanation:
Given
Object: Can (Cylinder)

Required
Maximize the volume
The surface area is:

Substitute 517.8 for S.A

Divide through by 2

Factorize:

Divide through by 

Make h the subject
--- (1)
Volume (V) is calculated as:

Substitute (1) for h

Open Bracket

Differentiate V

Set V' to 0

Collect Like Terms

Divide through by 3

Divide through by 



Take square root of both sides


Recall that:

Substitute 5.24 for r





Hence, the dimension that maximize the volume is:
--- Radius
--- Height
Yes, in this way we become more open minded and take in validated ideas of others.
Protective systems are methods of protecting workers from cave-ins of material that can fall or roll into an excavation, or from the collapse of nearby structures. As mentioned in earlier chapters, if an excavation is less than 5 feet deep, OSHA does not require a protective systems unless the competent person sees signs of a potential cave-in. (It is important to remember that a wall collapse in a trench four and 1/2 feet deep can still have serious results!) For trenches between 5 feet and 20 feet deep, shoring and sheeting, shielding, sloping and benching are all acceptable protective measures. It is up to the planners of the construction project and the competent person on site to determine which systems will work best. If an excavation is greater than 20 feet deep, a registered professional engineer must design the protective system.
Shoring systems are structures of timber, mechanical, or hydraulic systems that support the sides of an excavation and which are designed to prevent cave-ins.Sheeting is a type of shoring system that keeps the earth in position. It can be driven into the ground or work in conjunction with a shoring system. Driven sheeting is most frequently used for excavations open for long periods of time. Another type of sheeting, in which plates or shoring grade plywood (sometimes called Finland form) is used in conjunction with strutted systems such as hydraulic or timber shoring. These strutted systems are also referred to as active systems. The most frequently used strutted system involves aluminum hydraulic shoreswhich are lightweight, re-usable and installed and removed completely from above