_____earth scientists understand how and why earthquakes happen, forecasts are usually inaccurate. [ ]

A. As

B. While

C. Because

D. If

某货轮经过长沙港时不慎发生石油泄漏。环保志愿者取水样，欲对其进行分离。请简述他将进行的操作步骤：_____________________________________。