He thought that painting copied by a modern artist was ______ great value and bought it ____ over a thousand dollars.

A．at; for

B．of; for

C．of; at

D．for; by

某小型猪场，部分猪出现极度口渴、黏膜潮红、呕吐、兴奋不安、转圈、肌肉痉挛、全身震颤等症状，这些神经症状周期性发作。此外，病猪呈犬坐姿势，后期四肢瘫痪，昏迷不醒，有的衰竭而死。病猪的嗜酸性粒细胞数为（）

A.2%～3%

B.3%～4%

C.5%～6%

D.6%～10%

E.10%～12%