Excuse me, what does it mean to defend our country?

Simply put, it is to defend the motherland and the frontier, but the landlord has a typo, that is, the defense is different, and you can't confuse the defense (Shu) with the defense (Xu). The national defense (Shu) commemorative badge is right, the national defense (Shu) is right, and the national defense (Xu) belongs to China in ancient times.