未知题型 Compared to the yearly price changes that actually occurred on foreign agricultural markets during the 1880's American farmers would have most preferred yearly price changes that wereA.similar in size but in the opposite direction.B.much smaller and in the same direction.C.much smaller but in the opposite direction.D.slightly greater and in the same direction.

单项选择题 在书中叉车工作装置液压传动系统中，（  ）可防止重载缸逆行、轻载缸超速的现象发生。  A、单向节流阀中的单向阀 B、手动换向阀中的单向阀 C、溢流阀 D、限速阀

单项选择题 公费医疗的经费属于         。 A. 国民收入的初次分配 B. 国家的财政收入 C. 劳保医疗支出范围 D. 计划经济体制下的国民收入再分配