Cistine
氨基酸
🗣️ 情景例句
It is.
是的。
I'd like to make a reservation to Los Angeles for next Monday.
我想预定一张下周星期一去洛杉矶的飞机票。
I sat down on one of those modern chairs with holes in it and waited.
我坐在一个新式的满是网眼儿的椅子上，等待着。