zhè / pǐ / mǎ / yǎng / zài / cǎo / chǎng / shàng / zuì / jìn / dūn / biāo / dūn / de / hěn / kuài

这匹马养在草场上，最近蹲膘蹲得很快。

This horse is being raised on the pasture and has been putting on weight quickly.