End-to-end encryption and privacy controls.
Message and call for free* around the world.
Group conversations made simple.
Say it with stickers, voice, GIFs and more.
Reach your customers from anywhere.
https://tiengtrunghsk.net/giao-trinh-ngu-phap-hsk-4-chuyen-sau-bai-tap-luyen-thi-hsk-cap-4/