leading crop的用法和樣例：
例句
- Rice is the chief crop in most southern provinces.
稻子是大多數南方省份的主要作物。 - Triticum aestivum is the second most important crop in China and its production and quality are directly linked with both international and domestic affairs.
小麥是我國第二大主要作物，其產量與品質直接關係到國計民生。
