libration in longitude

例句：

1. 1. The surveyor measured the length of the river accurately.
   测量员准确地测量了河流的长度。
2. 2. The carpenter was asked to perform a libration on the building.
   木匠被要求对这座建筑进行经度测量。
3. 3. The scientist conducteda libration to determine the location ofthe sun.
   科学家进行了一次经度测量，以确定太阳的位置。