For companies like Shenhua, PetroChina, and Sinopec, do their Beijing headquarters recruit personnel internally? Or will they also recruit from the whole society?

Yes, many of them are internal recommendations, but some positions are recruited from the public. Now many oil fields have stopped recruiting. Sinopec and PetroChina are both, and internal recommendations are not required. However, Last time I saw on the Yilan Petroleum Talents website that they were still recruiting, but now I don’t know if they are still recruiting.