kē / xué / jiā / cóng / dà / cháng / gǎn / jūn / zhōng / tí / qǔ / zhì / lì / yòng / yú / jī / yīn / kè / lóng科学家从大肠杆菌中提取质粒用于基因克隆Scientists extract plasmids from E. coli for gene cloning.