乳癌最多见于：
A. 25～40 岁，50～54岁
B. 30～50岁，55～60岁
C. 45～49岁，60～64岁
D. 50～54岁
E. 40～60岁
大肠癌有哪些警戒信号：
A. 腹胀、腹痛、消化不良、食欲减退
B. 粪便带血（或出现黑便）及有下坠感
C. 排便习惯改变、便频便秘交替
D. 粪便形状改变，变细、变扁
E. 肠镜检查发现有结肠多发息肉或乳头状腺瘤
Which of the following best defines the breakeven point?
A. The amount needed to sell to achieve a certain level of profit
B. The number of units needed to be sold to cover all costs
C. Unit sales required to meet target profit
D. The marginal cost of producing one more unit
If the selling price of a unit of product increases, but nothing else changes, which of the following describes the impact of this on the breakeven point?
A. No change
B. More units need to be sold to breakeven
C. Fewer units need to be sold to breakeven
D. The margin of safety decreases
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