Tom look at Jenny, tears______his eyes, and shouted out the words______in his heart for years.( )
A:filling; having been hidden
B:filled; hidden
C:filling;hidden
D:filled; hiding
读北美洲地形简图,其中代表阿巴拉契亚山脉所处位置的代码是 ( )。
定义运算“@”的运算法则为:x@y=x+y-4,则(2@6)@8=____ .
保护环境 从我做起