例句與造句

1. A sharp tool, or bit, was hung from a rope and jerked up and down by men jumping on a spring-board .
   粗繩子上掛著銳利的工具，即鉆頭，由踏板上跳躍的人把它拉起又放下。
2. It's difficult to find spring-board in a sentence. 用spring-board造句挺難的