来自彭伟成的问题
Thecountryhasbeen__theborderdefenseinpreperationforwar.a)stretchb)stretchingc)suggestd)suggested
Thecountryhasbeen__theborderdefenseinpreperationforwar.
a)stretchb)stretchingc)suggestd)suggested


Thecountryhasbeen__theborderdefenseinpreperationforwar.a)stretchb)stretchingc)suggestd)suggested
Thecountryhasbeen__theborderdefenseinpreperationforwar.
a)stretchb)stretchingc)suggestd)suggested
b,意思是这个国家为了准备战争正加强边界防卫.
havebeendoing,已经正在做某事的意思