A:No, I’m sorry to say I’m still working for it
B:No, I need to see your passport
C:Yes. I think I saw one on the first floor
D:Yes, I do agree that it’s a good sho
古希腊数学家把1,3,6,10,15,21,…叫做三角形数,根据它的规律,第100个三角形数与第98个三角形数的差为( )
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1月份,黑龙江省冰天雪天时,海南岛依然百花盛开,这是因为( )