搜寻有用的资源。

Objectives

搜寻补给品次。

Tiers

1. 1 : 3 objectives completed
2. 1 : 10 objectives completed
3. 1 : 25 objectives completed
4. 1 : 50 objectives completed
5. 5 : 100 objectives completed
6. 5 : 250 objectives completed
7. 5 : 500 objectives completed
8. 5 : 1 000 objectives completed
9. 5 : 1 500 objectives completed
10. 5 : 2 000 objectives completed