总固定成本〔Total cost）
参考答案：
总固定成本是指每个时期厂商在不变投入品上的总支出。
日本血吸虫成虫刺激机体产生的免疫力可杀伤（）
A.成虫
B.尾蚴
C.童虫
D.虫卵
E.以上均可
The regulations require that inspected vessels on an international voyage，other than small passenger vessels，must carry which of the following distress signals on or near the navigating bridge?（）
A.12 hand red flares
B.12 rocket parachute flares
C.12 hand combination flares and orange smoke signals
D.6 hand red flares，and 6 hand orange smoke signals
