目前，国内对于微小型无人直升机的研究仍处在起步阶段。

The studies of micro-unmanned helicopter in our country are at the beginning.

youdao

目前，国内对于微小型无人直升机的研究仍处在起步阶段。

The studies of micro-unmanned helicopter in our country are at the beginning.

youdao