What should I bring when traveling to the Qinghai-Tibet Plateau? () ① Sunscreen ② Anti-ultraviolet sunglasses ③ Hat ④ Oxygen bag&; (=NationalBureauofStandards) ...

The main body of the Qinghai-Tibet region is the Qinghai-Tibet Plateau, which is known as the "roof of the world" and the natural environment is characterized by cold. The principle of carrying things is light and practical. "It is best to carry oxygen inhalation equipment", because the Qinghai-Tibet Plateau has high altitude, thin air, low air pressure and lack of oxygen; "It is best to wear sunglasses, sun hat and sunscreen for protective equipment" because the air on the plateau is thin and the solar radiation is strong; It is best to wear a hat and down jacket, because the temperature difference in the plateau is large and the temperature is low in the morning and evening.

So choose: C.