严格控制重介质选煤生产过程中的（），是降低选煤厂生产成本，提高综合经济效益的重要保证.
参考答案：介耗
Mr. Jenkin regretted _____ his secretary for the mistake, for he later discovered it was his own fault.[ ]
A. to blame
B. being blamed
C. blamed
D. having blamed
脉络膜转移癌的特点包括（）
A.患者多无明显眼部症状或无痛性视力下降
B.眼底多见多发黄色病灶
C.可伴有浆液性视网膜脱离
D.应主要治疗原发肿瘤，眼部可行放疗或化疗
E.以上均是
