If I'd know I was cming to a place that had nothing but fresh air, I would have brought a surgical mask.

如果早知道我要到一个只有新鲜空气的地方来的话，我就会带一只口罩来了。

youdao

If I'd known I was coming to a place that had nothing but fresh air, I would have brought a surgical mask.

如果早知道我来的地方只有新鲜空气，我就会带一只口罩来了。

youdao

If spraying application is carried out in a limited place like narrow booth, the operator must wear a ventilated mask with an air compressor for feeding filtrated fresh air.

如果喷涂施工是在狭小舱室内等有限空间进行时，必须佩戴通风面罩，以空压机不断送入经过滤处理的新鲜空气，以供操作者呼吸之用。

youdao