双重价格政策即当市场价格高于规定的最高价格水平时，政府大量购进农产品；当市场价格低于规定的最低价格时，政府抛售库存农产品。
查看答案
The Romans led by Julius Caesar launched their first invasion on Britain in ____.
A. 200
B. 55 B.
C. 55 A.
D. 410 A.D
Under William the Conqueror, the _____ were at the bottom of the feudal scale.
A. knights
B. lesser nobles
C. freeman
D. serfs
Under _____, the feudal system in England was completely established.
A. HenryⅡ
B. William Ⅰ
C. Richard Ⅰ
D. Henry Ⅴ
The feudalism was ended by ______
A. the Wars of Roses
B. the Hundred Years War
C. the English Civil War
D. the Glorious Revolution
微信支付 
支付宝支付