If I go to Bali, can I roam internationally with my domestic mobile phone? I heard that only three-frequency mobile phones can be used abroad. Is that so?

I just got back. As long as your mobile phone is used for international long distance and roaming, it can be used in Bali, but the charge is more expensive. I suggest you buy a phone card in Bali and call back to China. It's about 1 RMB one minute, and the local price is 50,000 rubles.

It is estimated that you should only contact China in Bali. Call back to China for 29.99 yuan a minute, answer the phone for 5.99 yuan a minute, and send a text message 1.99 yuan. Receiving text messages is free. I suggest you use a local card.