在职研究生英语（一）
阅读短文，选出填入空格最合适的一项： Farmers who spread tr…
第 1 题单选题模拟题较易
阅读短文，选出填入空格最合适的一项：
Farmers who spread treated sewage sludge on their fields may be adding plastic to the soil without knowing it, ___ the sludge often contains tiny fibers from washing machines that treatment plants cannot filter out.
逻辑关系完形填空上下文复现