B.door C.mats 相关知识点: 试题来源: 解析 B 问句中用的是is, 所以后面的名词用可数名词单数,故选择B。反馈 收藏
Alpaca wool is a type of wool that is derived from the fibers that naturally grow on alpacas. These animals are known as camelids since they are similar to camels, and alpacas are native to South America. There are two breeds of this four-legged animal: