cloudy的名词形式为“cloud”,并且“cloud”是可数名词: On cloudy days, we can see a lot of clouds in the sky. 在多云的日子......
healthy的反义词是unhealthy,healthy的名词是health。 看看这个词怎样一步一步变化的:heal(v. 治愈,修复)→health(n. 健康)→healthy(adj.......