x-ray (n., v., adj.): I think she should go for x-rays. The doctor will x-ray her arm. I saw the x-ray films.
Y
years—Use figures, without commas, for years with four or fewer digits: 1948, 1776. Use figures, with commas, for years with five or more digits: "Radiocarbon dating indicates that the campsite was in use by about 13,500 B.P." When designating eras with B.C. or A.D., the abbreviation A.D. precedes the year, and B.C. follows it: "Britain was invaded successfully in 55 B.C. and A.D. 1066." (31)
- Use s (no apostrophe) to indicate spans of decades or centuries: the 1890s, the 1900s. (See plural figures and letters.)
- Set off a year with commas when it follows a month and date: The Senate approved the recommendation at its April 13, 2007, meeting.
- Do not use a comma to separate a month and a year: June 1988.
- Years are the sole exception to the rule of spelling out numbers that begin sentences. (See numbers, figures or words? )
Z
zero, zeros
(31) Chicago Manual of Style, 14th edition (1993), 8.41
