parenthesis的复数，圆括号
A string of one or more characters used to separate or organize elements of computer programs or data; for example, parentheses, blank character, arithmetic operator, if, "BEGIN". 用来分隔或组织计算机程序元素或数据元素的字符或字符串。例如括号、空格符、算术运算符、if(如果)、“BEGIN＂等。
In assembler programming, one or more operation represented by a combination of terms and paired parentheses. 汇编程序设计中，用项和括号对的组合所代表的一个或多个操作。
