How to abbreviate background-size to background?

I read this article ( https://www.jianshu.com/p/fa0.) introduction

originally:

background: url(xxx);
background-size: 10px 10px;

the abbreviation is

background: url(xxx) / 10px 10px;


but it doesn"t work! I am chrome 70.0.3538.77

Oct.26,2021

refer to this article, Portal


/ preceded by 0


background: url(xxx) (left|center|right|) (top|center|bottom|) /   ;
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1bf699a-536a8.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1bf699a-536a8.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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