例句與造句

1. Congestion of the mucosa is a variable sign .
   粘膜充血是不恒定的表現(xiàn)。
2. Led variable sign of road traffic guide
   Led道路交通誘導(dǎo)可變標(biāo)志
3. It's difficult to find variable sign in a sentence. 用variable sign造句挺難的