我们知道，任意一个正整数n都可以进行这样的分解：n=p×q（p，q是正整数，且p≤q），在n的所有这种分解中，如果p，q两因数之差的绝对值最小，我们就称p×q是n的最佳分解．并规定：F（n）= $\frac{p}{q}$ ．例如12可以分解成1×12，2×6或3×4，因为12﹣1＞6﹣2＞4﹣3，所有3×4是12的最佳分解，所以F（12）= $\frac{3}{4}$ ．

2011年5月12日，南方都市报消息，2011年影响广东沿海的风暴潮预计有4～6次，南海海域灾害性海浪预计有8～10次，广东沿海预计有4～6次。据此回答：

诱发广东的风暴潮的因素主要是(   )

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                                                                Table manners in America

        Don't circle your plate with your arms. If you do so, you will become the focus  (焦点)  of the table. Everyone would wonder, "Is there anything wrong with the food?" This may give a wrong message that you don't like the food or something like that.

       Don't push the plate back when finished. Leave it where it was. Do you want to let the hostess (女主人)(1)_________(know ) that you've just done a labours。

        Don't lean (倚靠) back and say "I'm through" or "I'm full". Just put the fork and knife across the plate. That's all. 

       (2)Don't cut up everything before you start to eat. Cut only one or two bites (块) at a time. Never take a huge mouthful of anything. Do you want to show how hungry you are? Don't do that. It's not so good.

        It's never good to reach across the table for anything. If the thing you want is not at hand, simply ask the nearest person for help, like "(3) Mrs. Smith, could you pass me the dish?"