Birefraction
双折射
🗣️ 情景例句
autograph copies for the guests at the opening?
在展览开幕时为客人在书上亲笔签名呢
The plane has crashed.
飞机失事了。
I will have to choose presents for all the family soon, but I haven't chosen any yet!
我很快就要为每一位家庭成员选购礼物，但我至今还什么也没买！