前哨
?outpost
?advance guard
在月球上建立一個～，作為在火星上登陸之用的中間整備區(qū)域establish a lunar outpost to serve as a staging area for a Martian landing/社會主義的～outpost of socialism/雙方的～advance guards of the two sides/外交工作的～ outpost of diplomacy/與敵人～接觸skirmish with the enemy’s advance guards/～戰(zhàn)skirmish