Et cetera is abbreviated to etc. No second period is needed but you will sometimes find one anyway.
No, you do not put an extra period after "etc." since the period at the end of "etc." serves as the ending punctuation for the sentence.
Either a period ( . ) or an ellipsis ( . . . ) will go after 'etc' .
No, you do not need to add an additional period if "etc." is within parentheses at the end of a sentence. The period that ends the abbreviation "etc." also serves as the sentence-ending punctuation.
Age, era, period of time etc.
A dot is used to express missing letters but is not needed if the abbreviation includes the last letter of the word e.g. Mrs, Mr, Dr etc. Therefore Co. needs a dot but Ltd does not.
It's a shorter way of saying "menstrual period" as opposed to other kinds of periods, such as orbital periods, periods of time, etc. The etymology of the word is something along the lines of "Interval, season, time, circuit" etc.
yes, most probably
After all titles for example: Mr. Mrs. Dr. Rev. Ms.,etc.
If a sentence ends with an abbreviated word then only one period (full stop) is used.
Yes there should be a period.
One period. The period in etc. also functions as the period for the end of the sentence.