jǐhéguāngxué
ㄐㄧˇ ㄏㄜˊ ㄍㄨㄤ ㄒㄩㄝˊ
Simplified 几何光学
Taivo → Settings → Partner inbox → Make the link. It stays in this browser.
Keep 幾何光學 and it comes back until you know it.