阅读下面短文，掌握其大意，然后从各题所给的四个选项中选出可以填入空白处的最佳选项。

Life is not always easy and everyone may meet with difficulties. When I was in Grade Seven, I was very poor at maths and once even wanted to ___. My maths teacher noticed this and had a long talk with me after class. She told me that the ___ to success was hard work and patience. From then on I began to ___ much more time on maths than before. Little by little I caught up with my classmates. Now I know nothing is impossible ___(4) you put your heart into it. Difficulties can make us ___ if we face them bravely.

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