Sanvista
电子色盲治疗仪
🗣️ 情景例句
(a foreigner) Is that a special day?
（一个外国人）是一个特殊的日子吗？
That house is for sale.It has central heating.
那幢房子是待售的，它有中央暖气系统。
a wave length (the horizontal distance between two wave crests),
波长（两个浪峰间的水平距离）