upset bolt

例句：

1. 1. The sudden drop in the stock pricehas left the company's board ofdirectors upset.
   股价的突然下跌让公司的董事会感到心烦意乱。
2. 2. Thecar was so old that it needed anupset bolt to fix it.
   这辆车太旧了，需要一颗松动的螺栓来修理。
3. 3. The engineer had to replace theupset bolt before he could start theengine.
   工程师在启动引擎之前不得不更换那颗松动的螺栓。