Undo is Ctrl-Z. Undo buttons also exist in most non-Notepad text editing programs.
Answer:
Yes
Explanation:
A nonlinear optimization problem is indeed a optimization problem in which there are nonlinear elements involved either as the objective function or one or more constraints may be nonlinear also. Let me show you an example. Let optimize de following function:

These are the constraints:

The last constraint consists on nonlinear elements, so this problem in fact a nonlinear optimization problem.
Answer:
ring network
Explanation:
In a ring network, the nodes are arranged in a circular pattern where each node is connected to two adjacent nodes. In this topology, any node can communicate with any other node via the intermediaries.
In comparison,
- in a star network every communication needs to pass through a central hub node
- in a bus, each node is connected to a shared linear communication bus.
- in a hierarchical network nodes are organized along a tree structure layout.
also called lime, silica glass, is the most prevalent type of glass, used for windowpanes and glass containers (bottles and jars) for beverages, food, and some commodity items. Glass bake ware is often made of borosilicate glass.