拉普拉塔河总督辖区建立于（）。
A.1490年
B.1492年
C.1719年
D.1776年
参考答案：D
样本数据：2，50，45，88，36的极差是______．
. -- Jack _______ for work in the downtown. What was the matter?
-- _______, but he had no luck.
A．ought to have hunted; So he was
B．ought to have hunted; So he did
C．ought to hunt; So he has
D．ought to hunt; So he did
