引进以来，共有四架飞机坠毁，其中包括一架单座机和三架双座机。

Since its introduction, a total of four planes crashed, including a single machine and three pairs of machine.

youdao

引进以来，共有四架飞机坠毁，其中包括一架单座机和三架双座机。

Since its introduction, a total of four planes crashed, including a single machine and three pairs of machine.

youdao