根据句意和汉语注释，写出单词的正确形式。
This year’s Spring Festival is on the _________ (十九) of February.
I got a big surprise at Christmas and it was really hard to __________（描述）my joy in words.
Mike, if you eat too many sweets, you may get a __________ (牙疼).
Don’t worry about your son. His temperature __________ (下降) back to37℃ just now.