书写需要的协同力主要指手眼协调能力。(   

单项选择题6)An economist’s definition of profit differs from that of an accountant because A、.the economist is only interested in marginal cost and marginal revenue. B、.the economist includes the opportunity cost of owner-supplied inputs in total cost. C、.accountants cannot maximize. D、.economists cannot add or subtract correctly.

单项选择题某猪场的一批5月龄育肥猪,体温和食欲正常,但生长缓慢,个体大小不一;经常出现咳嗽、气喘等症状。剖检见肺部尖叶、心叶、膈叶前缘呈双侧对称性肉变,其他器官未见异常。诊断隐性感染猪的快速方法是(2010真题下169) A. X线检查 B. PCR检查 C. 病原分离 D. 白细胞计数 E. 免疫荧光检查