True false the table can have only one primary key

Which number on the image above correctly indicates the name of a folder in this url? a.1b.2c.3d.4

Laire writes a letter to her grandmother, in which she describes an amusement park she visited last week. she adds pictures of that place in her letter. which feature of a word processing program will claire to remove unwanted parts of the pictures?

In excel - calculate the actual increase/decrease from first quarter to the second quarter then subtract subtract first quarter value from second quarter total then divide result by first quarter value