从3名骨科、4名脑外科和5名内科医生中选派5人组成一个抗震救灾医疗小组，则骨科、脑外科和内科医生都至少有1人的选派方法种数是______（用数字作答）．
直接法：3名骨科、1名脑外科和1名内科医生，有C33C41C51=20种，
1名骨科、3名脑外科和1名内科医生，有C31C43C51=60种，
1名骨科、1名脑外科和3名内科医生，有C31C41C53=120种，
2名骨科、2名脑外科和1名内科医生，有C32C42C51=90种，
1名骨科、2名脑外科和2名内科医生，有C31C42C52=180种，
2名骨科、1名脑外科和2名内科医生，有C32C41C52=120种，
共计20+60+120+90+180+120=590种
故答案为：590．
| 根据对话内容,从方框内选择合适的句子补全对话。(有两项多余) | |
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| M: Hey, Li Fei. Would you like to see a movie tomorrow evening? W: I'd love to. (1)___________ M: Aftershock has been on since 12th July. (2)___________ W: I'm afraid not. It will make me sad and I don't like sad movies. M: (3)__________ W: Feng Xiaogang's comedies are all very good, like A World Without Thieves which makes me so happy every time I see it. M: Oh, I see. But I think you should try a different one. It's really moving (感动人的). W: (4)___________ M: No, I haven't. But some of my friends have seen it and they all said they were moved to tears by the great family love in the movie. W: (5)___________ So, see you at the cinema tomorrow evening. M: That's good. Let's meet at 7 o'clock. W: OK. |