1.I can’t remember all these great ____explorers'( 探险家们的）__________(explore) names.
2.Let’s see what____has happened____(happen) in the last few years.(in the last few years是现在完成时的时间状语）
3.The cars are those _____Germans'(那些德国人的）.but they’re made in China.
4.They are waiting for you at the front__entrance（人口）__ to the building.