由于某种原因，种群进入新地区后得到迅速扩展蔓延，称为______。
参考答案：生态入侵
Much to our _____, China won 51 gold medals, more than any other nation, at the 2008 Beijing Olympic Games.
A．regret
B．delight
C．disappointment
D．sadness
什么叫失光？
