1. A dry, often sandy region of little rainfall, extreme temperatures, and sparse vegetation. 下雨很少，温度极高，植被贫乏的干燥，通常多沙的地区。
2. Data structure in the knowledge of the matrix, sparse matrix, pattern matching, a special matrix, string, etc. 数据结构中有关矩阵的知识，稀疏矩阵，模式匹配，特殊矩阵，字符串等知识。
3. The man increased his price to $25 each and the supply of monkeys became so sparse that it was an effort to even see a monkey, much less catch one. 该名男子增加价格到每只25美元，但是猴子的供应变得更稀少，再怎麽努力都很难见到一只猴子，更别谈抓猴子了。
