grain crop的用法和样例：
例句
- Although perennial crops, such as alfalfa and sugarcane, already exist around the world, none has seed yields comparable to those of annual grain crops.
虽然世界各地已有一些多年生作物，像是苜蓿和甘蔗等，但它们的种子产量都无法与一年生谷类作物相比。 - In fact, the grain does address some of the concern between market liberalisation and called to reduce the dominance of international markets and the corporations controlling them.
事实上，谷类作物并没有引起我们对自由主义市场的关注，也没有减少国际市场的支配，合作和控制作用。
