[填空题]
What is the dew point z s-tl;5w)id57k :gu l9vkhsv(approxima.iy87 syj xiyuq bkb3s;u 6t/:tely) if the humidity is 50% on a day when the tempiub:u63bikysyxqt /. 7ysj;8erature is 25 $^{\circ} $ C?$\approx$ $^{\circ} $ C(Round to the nearest integer)