Opportunities are always＿as long as we use our minds．

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The reader who has spent serious effort on a problem may________ from the effort even if he does not succeed in solving the problem．

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It is said that ________mammals such as whales and seals may communicate with each other verbally deep under the water．

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The thing than ________is not whether you fail or not，but whether you try or not．

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________with Dick you are more diligent．

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It is said that constant reviews of what you have learned will help make your knowledge________．

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I invited Joe and Linda to dinner，but________ of them came．

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Although these few words sound simple enough，they have ________pointed out one of the causes of the population explosion．

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Uncle Ben will com back for Christmas．I'm sure we'll have a________ time together．

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I used to play ping ________pong a lot in my spare time，but now l am ________in football．

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