[判断题]1927年3月,上海工人第二次武装起义胜利,北伐军顺利进驻上海。
A.正确
B.错误

The historian Frederick J. Turner wrote in the 1890’s that the agrarian discontent that had been developing steadily in the United States since about 1870 had been precipitated by the closing of the internal frontier that is, the depletion of available new land needed for further expansion of the American farming system. Actually, however, new lands were taken up for farming in the United States throughout and beyond the nineteenth century. (46) In the 1890’s, when agrarian discontent had become most acute, 1,100,000 new farms were settled, which was 500,000 more than had been settled during the previous decade. After 1890, under the terms of the Homestead Act and its successors, more new land was taken up for farming than had been taken up for this purpose in the United States up until that time. (47) It is true that agricultural practices had become sufficiently advanced to make it possible to increase the profitability of farming by utilizing even these r