Warning: file_put_contents(/www/wwwroot/ppbbu/laei.cn/cache/cd3fc6e222b5140ef897181a6b35fdfe.txt): failed to open stream: No space left on device in /www/wwwroot/ppbbu/laei.cn/index.php on line 58 jack-screw是什么意思，jack-screw的翻译，jack-screw音标、读音、用法和例句_按摩法牛津词典
Each of the four legs contains a simple screw jack with a thrust bearing that is operated telescopically inside of two tubes. 四条腿中每个都装有一个简单的螺旋千斤顶，千斤顶中又有一个在两根管道中做伸缩操作的推力轴承。