Contravalid
反有效的, 无效的
🗣️ 情景例句
Butter, nice and cold and hard.
牛油 新鲜又冷又硬。
Do I need a reservation for the dining car?
我需要预订餐车吗？
The Hubble telescope was launched into space by NASA on April 20,1990 at a cost of over a billion dollars.
哈勃望远镜于1990年4月20日由国家航空航天局发射升空，耗资10多亿美元。