1. Take gaining profit at Shanghai Future Goods Exchange Centre for example, investors gained profit from in-stock gold price at 22 Yuan/g on January 9th 2008 the first day of Shanghai 0806 contract future gold went on the market. Except financial dect 1.665 Yuan/g, 2% of open interest freeze consumption, different commissions 1.2 Yuan/g, investors could have opportunities of gaining profits only when material future goods price is less than the golden area illustrated in the above pictures on the first open day on the market. If investors could make sure future goods price expiration and the actual price shock is limited in a scale while the scale shock is limited in the golden area, the investment risks will greatly decrease. Syphonage theory deems that if investors could select a golden area whose shock scale is limited in the golden area and select a package whose profit aim shocks stay far from risk boundary. In most cases, to say that profit gaining exchange cannot get infinite profits as expected is not an exaggeration, due to different national gold exchange system. The result of profit gaining exchange is to limit the lever percentage of risk investors. In actual profit gaining process, investors should choose suitable type to operate.
实际运作时应主意国家黄金财政政策限制了某些类型套利获利空间，以在上海期货交易所套利为例，投资者在2008年1月9日上海黄金期货0806合约上市首日，利用和上海黄金交易所黄金现货价格22元/克的价差进行套利，除去财政扣减1.665元/克、开仓冻结资金利损2％、各项佣金手续费1.2元/克，如黄金期货上市首日套利为例，九五金和黄金期货0806品种在上海进行期现套利时，只有当实际期货价格小于上图期现套利示意图金色区域时，套利者才有机会获利，例如投资者确定未来期货价格到期时，实际价格波动范围在一定区间内，同时该区间波动幅度不会超出图中金色范围，则投资风险会大幅减小，虹吸理论认为投资者a尽量选取能创造较大范围金色区间，并且套利目标波动距离远离风险边界的套利组合进行套利，很多时候套利交易在有些国家黄金交易制度等因素影响下，并不能获得传说中无限的利润空间，这决非危然耸听，套利交易的结果等于是缩小了风险投机者的风险收益杠杆比例，在实际套利过程中，投资者应选择合适的品种进行操作。
2. I cannot say for sure if it was your visual illusion.
我不能肯定这是不是你的视错觉。
3. Nearly two full days after the explosion in North Korea, U. S. officials, including Pentagon Spokensman Bryan Whitman cannot say for sure whether it was a nuclear explosion or not.
北韩的爆炸已经是两天前的事情了，美国官方，包括五角大楼的发言人布莱恩惠特曼表示仍然不能确定这是否是核爆炸。
4. I think he lived in Shijiazhuang, but I cannot say for sure.
我想他是住在石家庄，但是我不敢肯定。
5. We cannot say for sure what will happen
我们无法确定会发生什么事。
6. I cannot say for sure if it was your visual ********.
我不能肯定这是不是你的视错觉。
7. I cannot really say for sure that Malta have improved lately, but I hope so.
我真的不能肯定地说，马耳他已在近期有所改善，但我希望如此。
8. Why people cannot have a doubt on some so-call newage theory and haveto believe in what you say for sure?
为什麼人们不可以对你所谓的new age理论有怀疑还有一定要去相信你所说的事情？
1. We cannot say for sure the diseases are the direct cause of pollution.
2. We cannot say for sure that the mechanism will completely fail to resolve the irregularities and unethical practices afflicting the healthcare industry.
3. I cannot say for sure that they are what Stout describes as sociopaths.