自2010年至今的四级考试中， 共出现过 次
自2010年至今的六级考试中， 共出现过 次
N-COUNT （收入、年龄、价格等的）范围，等级段 If you say that someone or something is in a particular bracket, you mean that they come within a particular range, for example a range of incomes, ages, or prices.
...a 33% top tax rate on everyone in these high-income brackets...
Do you fall outside that age bracket?
N-COUNT （固定在墙上的）托架，支架，角撑架 Brackets are pieces of metal, wood, or plastic that are fastened to a wall in order to support something such as a shelf.
Fix the beam with the brackets and screws.
...adjustable wall brackets.
VERB 把…归为一类；把…相提并论 If two or more people or things are bracketed together, they are considered to be similar or related in some way.
The Magi, Bramins, and Druids were bracketed together as men of wisdom...
Austrian wine styles are often bracketed with those of northern Germany.
N-COUNT 括号，括弧（美国英语中称作parentheses） Brackets are a pair of written marks that you place round a word, expression, or sentence in order to indicate that you are giving extra information. In British English, curved marks like these are also called brackets, but in American English, they are called parentheses .
The prices in brackets are special rates for the under 18s...
My annotations appear in square brackets.
N-COUNT （数学上的）括号 Brackets are pair of marks that are placed around a series of symbols in a mathematical expression to indicate that those symbols function as one item within the expression.