有一些植物需经过低温后才能开花并成长结实。通过低温诱导促使植物开花结实的作用称为春化作用。
A. 洋葱开花影响其品质，因此在春季种植前高温处理越冬贮藏的鳞茎，以降低其感受低温的能力，从而得到较大的鳞茎
B. 使用赤霉素，二年生天仙子、白菜、甜菜和胡萝卜等不经低温处理就可以开花
C. 将萌发的冬小麦种子装在罐中，放在冬季的低温下40至50天后在春季播种，可获得和秋播同样的收成
D. 在第一年将二年生药用植物当归的块根挖出，贮藏在高温下，以减少第二年的抽蔓率而获得较好的块根
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下面四个所给的选项中，哪一项能由左边给定的图形拆成？()
设y=f(x)存点x处的切线斜率为2x+e-x，则过点(0，1)的曲线方程为
A. x2-e-x+2
B. x2+e-x+2
C. x2-e-x-2
D. x2+e-x-2
All of the following are mentioned in Paragraph 4 as results of the introduction of the heavy plow EXCEPT
A. a rise in trade with the peoples of Eastern Europe.
B. a change in the standard shape of farm fields.
C. an increase in the communal undertakings of farmers.
D. a decrease in the time needed to prepare fields for planting.
According to Paragraph 5, what was the benefit of using horses to plow fields instead of oxen？
A. They required less food during the day.
B. They pulled heavier loads.
C. Their necks were less susceptible to strain.
D. They worked faster and longer.
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