by a head的用法和样例：
例句
用作副词 (adv.)
- The mare was beaten for a place by a short head.
那匹母马以不到一头之差屈居第二名。 - It usually suggests that the head is low.
此字通常含有垂头之意。
词汇搭配
- win by a head 以一颈之差得胜(以微...
- by a short head 一头之差(相距极近)...
