Section breaks are powerful tools in document design and formatting
which option is not a good reason to use a section break?
using section breaks to create a separate section and insert a landscape orientation page within a document
using section breaks to insert new pages where needed
using section breaks to separate parts of the document and enable the link to previous function
using section breaks to enable the insertion of different headers and footers in different sections

A-12.3 an american spy is deep undercover in the hostile country of phonemia. in order not to waste scarce resources, any time he wants to send a message back home, he removes all the punctuation from his message and converts all the letters to uppercase. so, for example, to send the message, “abort the plan! meet at the dark cabin.” he would transmit given such a string, s, of n uppercase letters, describe an efficient way of breaking it into a sequence of valid english words. you may assume that you have a function, valid(s), which can take a character string, s, and return true if and only if s is a valid english word. what is the running time of your algorithm, assuming each call to the function, valid, runs in o(1) time?