很多人都没有被告知什么时候更换安全面罩的过滤网。

Some are not instructed in when to change the filters on their safety masks.

youdao

配有安全扣的全面部遮阳面罩，配有螺丝紧固件，以及泡沫密封条，遮阳面罩可以容易地安装在头盔及卸除。

Polycarbonate full-face visor complete with peak and safety latch. Supplied with screw fasteners, and a foam sealing strip, the visor can be easily attached and removed from the helmet.

youdao

配有安全扣的全面部遮阳面罩，配有螺丝紧固件，以及泡沫密封条，遮阳面罩可以容易地安装在头盔及卸除。

Polycarbonate full-face visor complete with peak and safety latch. Supplied with screw fasteners, and a foam sealing strip, the visor can be easily attached and removed from the helmet.

youdao